go with anything made by DEI (viper/python/cliford/avatal/ect) and they do make an add on piece for DEI alarms its called a proximity sensor and you put it in the center front of the truck and its for convertibles jeeps k5s anything topless and it will set it off if anything is detected inside the truck motion wise its adjustable also so you can bring the range of motion in and out its easy to set up also
i have a python 990 in my 03 chevy its an page back remote start alarm great thing about dei im using a viper remote and a cliford remote with the alarm different colors and a little different shape i use the viper one and my girl uses the cliford all dei remotes forthe same motel alarm and some different models are enter changeable
my 77chevy im using an autopage also a page back remote start alarm cant remember the model has all the same features as my viper only difference ive found the remote batterys last longer in the autopage and it has a clock on it
both work well ive installed dei for years profesionally but got both alarms for 35 a piece so i bought them both i do barley favor the auto page a little better but this is the only model ive personally used for more then just testing/demoing
if you go with DEI id go with a avatal or python same companies as viper totaly inter changeable only differents color of remotes and for some reason arnt as popular and usally cost is less some of the older avatals buttons glowed in the dark also came in handy alot
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