6 Best Car Alarms to Prevent Car Theft in 2021

Your car is just as important as your home, given the amount of money you spent buying it; And because it is so valuable, it is one of the most targeted objects for burglary. 

Aftermarket car alarms are in robust demand these days, despite the sophisticated factory-equipped anti-theft systems in modern vehicles. Thieves seem to find loopholes in modern technology. 

As per the National Insurance Crime Bureau, there were 873,080 auto thefts in 2020, a 9.2 percent increase over 2019 which had 799,644 thefts, a boost of more than 73,000 thefts.

Apart from adding an extra layer of protection for your vehicle, car alarms can lower your insurance premium. However, be sure to check with your insurance company first. 

What to consider when you buy a car alarm?

Although most modern cars are equipped with an alarm system, they are not enough to discourage professional thieves. Similar to motion sensor alarms, car alarms alert you via a loud siren and sometimes LED lights too. 

However, there are several things to consider when buying a car alarm system.

Compatibility with your vehicle – You must check whether or not an automotive alarm system is compatible with your vehicle. It is of no use if you buy an expensive product that does not work due to incompatibility.

One-way or two-way alarms – The difference between 1-way and 2-way car alarms is that one-way alarms set off a siren and LEDs, while two-way alarm systems do that and also send you real-time alerts. Sometimes you may need to park your car a few blocks away. Moreover, the benefit of a two-way alarm is that you get alerts on your remote if someone tries to break into your vehicle.

Operating range – This is an important feature to look for when buying a two-way car alarm system. If you park your vehicle outside a quarter-mile distance, look for a car alarm with a longer range. 

Carjack protection – Carjack protection refers to a set of features that actively prevent car theft. Kill switches, high-pitched alarms, and chirp alerts are among the options that may annoy the burglar into leaving your vehicle.

While these preventive controls may appear unnecessary, they have proved to effectively dissuade car thieves.

a. Encrypted transmission – With technological advances, thieves have become tech-savvy too. Some may hack into your car alarm system and disarm it. Therefore, you may want to look for alarms that offer added encryption for extra security.

b. Ease of installation – Installing a car alarm system involves a lot of wiring and tinkering with the electrical system of your vehicle. We suggest expert installation because it can be complex. However, this can add to the cost of the car alarm system. You’re not alone if you wish to try your hand at DIY installation. Many car owners fit their vehicle alarm system effectively. However, be cautious that DIY installation may void any equipment warranties.

Best Car Alarm Systems to Buy in 2021

Here is a list of the top 7 car alarms to protect your car from theft.

1. Compustar CA7900-AS All-in-one 2-Way Remote Start and Alarm Button

Compustar CA7900-AS All-in-one 2-Way Remote Start and Alarm Button


  • Product dimensions – 10.24 x 7.05 x 3.78 inches
  • Alarm intensity – 105 dB
  • One-way/ Two-way – Two-way

The wide range of features and the solid build of the Compustar All-in-One car alarm system makes it one of the best alarms for your car. It offers a 105-decibel alarm paired with LED lighting to alert you about a possible theft of your vehicle. A shock sensor alerts you if an intruder tries to use force to get access to your vehicle.

The car alarm system has a control fob with a 3000 feet range, that you can start with a remote. It allows you to pre-cool your car on a hot day, or pre-heat it during winters. However, this may require additional equipment depending on the vehicle. 

As a downside, you need the help of a professional to install it. 


  • Remote start feature
  • 3000 feet range
  • Pre-heat and pre-cool your car


  • Professional installation required
  • Some features require installing additional equipment

2. Viper 3100V 1-Way Security System

Viper 3100V 1-Way Security System


  • Product dimensions – 7.3 x 5.3 x 4.7 inches
  • Alarm intensity – 130 dB
  • One-way/ Two-way – One-way

The Viper car alarm is a perfect option if you are looking for a budget product. It is a basic alarm that alerts you through a loud alarm and flashing LEDs. Apart from alerting you, the alarm and the bright LEDs scare away any intruder. 

The car alarm also offers a central locking feature but you will require additional parts for it. You can easily install it yourself, but it is recommended to use professional installation. 

If you are looking for more advanced features, you should look at other options on the list. This car security alarm is a simple device that focuses on one job – discouraging a thief by drawing a lot of attention to it. 


  • Easy installation
  • Central locking feature (required additional parts)
  • Flashing LEDs


  • No additional features

3. Avital 5305L Security System for Cars

Avital 5305L Security System for Cars


  • Product dimensions – 6.5 x 6 x 6.5 inches
  • Alarm intensity – 130 dB
  • One-way/ Two-way – Two-way

The Avital 5305L car alarm system is a top-of-the-line security system for your car that comes with a two-way LCD remote. You can expand the car alarm system on other vehicles and control up to 4 different vehicles with a single remote. 

A confirmation message follows when you arm or disarm your car. The remote beeps and vibrates when the siren sounds so you can take immediate action. 

You can preheat or pre-cool the car depending on your needs. 

You can upgrade the device to allow for remote starting. It can start your car from up to 1500 feet away and confirm it has started on the remote control.

Although the company says that it is a DIY car alarm, customers recommend getting it installed by a professional. Also, unfortunately, the device does not work for vehicles with manual transmission.


  • LCD remote
  • 1500 feet range
  • Pre-heat and pre-cool options


  • Does not work for manual transmission vehicles

4. Compustar CS4900-S Car Alarm System

Compustar CS4900-S Car Alarm System


  • Product dimensions – ‎8.16 x 5.16 x 3.39 inches
  • Alarm intensity – unknown
  • One-way/ Two-way – Two-way

The Compustar CS4900-S car alarm system is a wonderful middle-of-the-road option for car aficionados, combining affordability and functionality. It is compatible with a wide range of automatic transmission cars, including diesel engines.

This Compustar auto alarm package includes two keyfobs that can lock and unlock your vehicle from a distance of up to 3,000 feet. You may also use the same fobs to access your trunk or start your car from afar.

You can install the Compustar CS4900-S car alarm system yourself with a little automotive know-how—no professionals needed.

Many car alarms, particularly those with remote starting capabilities, can be difficult to set on your own, yet review after review praised the directions and ease of use. However, before getting started, it is beneficial to have some wiring experience.


  • 3000 feet range
  • Access to trunk and auto-start option via the same remote


  • May require professional installation if you do not have any wiring experience

5. Mengshen Anti-Theft Car Alarm

Mengshen Anti-Theft Car Alarm


  • Product dimensions – 1.57 x 0.74 x 3.74 inches
  • Alarm intensity – 113 dB
  • One-way/ Two-way – One-way

The Mengshen Anti-Theft car alarm is a blaring 113-decibel alarm to keep your vehicle safe from theft. It is a simple battery-powered device that fits on your car, motorcycle, or bicycle. 

You can arm or disarm your vehicle with a remote control that has a 20-meter range. Also, you can adjust the touch sensitivity as per your requirement. The car alarm activates when it detects vibration or a “shake” and alerts you with a blaring alarm. Additionally, you can choose from over alarm 6 ringtones.

Installation is easy – simply paste the device on your vehicle using the double-sided sticker. It is one of the most convenient and cheap car alarms available in the market. 


  • Easy to install
  • Adjustable alarm sensitivity
  • Over 6 alarm ringtones to choose from


  • No additional features
  • Only 20 meters range

6. Viper 350 PLUS 3105V 1-way Car Alarm

Viper 350 PLUS 3105V 1-way Car Alarm


  • Product dimensions – 7.4 x 4.1 x 5.5 inches
  • Alarm intensity – 113 dB
  • One-way/ Two-way – One-way

The car alarm by Viper is an innovative car alarm that ensures that thieves do not lurk near your vehicle. It has a failsafe starter kill system and anti-carjacking mode that makes sure that your vehicle is not stolen. 

The shock sensor gives out warning chirps for minor disturbances to discourage the thief. However, if the person is undeterred, the sensor trips the alarm to sound a blaring alert. 

It is an easy to install car alarm and comes with a detailed step-by-step instruction manual to aid the installation. 


  • Anti-carjacking feature
  • Shock sensor that gives pre-warning siren for minor disturbances
  • Blaring alert for undeterred thieves


  • You may not hear the alarm if the car is parked far from you


Investing in a car alarm is one of the best decisions you can make for the safety of your car. We hope this list of the best car alarm systems has helped you buy an ideal product as per your requirements. 

If you have previously owned a car alarm, tell us via the comments how it helped protect your car, and why do you want to upgrade it? 

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