I just replaced my 8 year old Python system with a Viper 3105 V It is almost just like my old system. The keyless entry is grate. I missed my old one when it quit on me. I had to replace it with a new system after about 1 week. The install was not bad, because I already had a system in the truck. If you are not good with relays and how they work, I suggest you do not install a system yourself. All the alarm systems need relays to make them work correctly.