Viper by directed is a good dependable alarm system with a couple add-on sensors and a 4g gps module your vehicle will be more secure than your own home, with that add-on module you can use the phone app and start your vehicle from anywhere on the planet, track it, put up a digital fence, get a text, email and a fob alert if anyone tries to break into it.
for audio the infinity kappa series is a pretty good bang for the buck
kenwood and pioneer both offer wireless android auto/apple carplay head units
backup cam can be added as well
throw in a hotspot and a roku and you can have mobile streaming video..
sky's the limit
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