2008 grand prix remote start

I have a 2008 Pontiac Grand Prix I want to install a new remote start system in with a nice range. Currently i have the factory installed remote start system, my question is this. How much more (if any) difficult is it to install something like the Audiovox XR09100, the XR9000 or the XR6900 with the car having the factory installed stuff? what all is involved? This is just the beginning of the electronic mods I am doing, but the most important if you ask me.

A better bet might be to look in to some of the range extending antenna systems available from Bypasskit and others. Bypasskit doesn't explicitly list your vehicle in the manual for their XTR-LINK, but several other similar GMs are there so I think it would work. Those are cheaper and much easier to install than an entirely new remote start would be.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two