I just bought a 2003, 330ci. the dealer said there was an alarm, but it turns out there is not one. They are going to install one free of charge. Asked me if i want them to install the bmw alarm (which my car is prewired for) or install a viper alarm. I don't know what the pluses and minuses are for both...i want to be able to control it via my BMW key, not thru another key fob. any one have any input or suggestions?