Has anyone installed an aftermarket keyless entry/alarm system, like they sell at ebay? I have the wiring diagram, although I'm not sure I know what it all means. (I have installed plug and play speakers, but that's about it as far as my car electronics experience). Is the process all about splicing in wires, or is there a lot more to it? As long as I don't cut the airbag wire or anything, is can I really mess things up? I know I'll need a solenoid to get the trunk to open at push of a button...The Maxima has the double pulse doorlock system and someone said I'll need to buy an adapter for that. What does that mean, and are there any other pieces I'll need to buy? Thanks!