I had a Python alarm/remote start, worked well, but I am just a guy that likes everything stock, and the 2-way remote was to bulky...

 

I have to agree with mrspike, I like to have everything stock, unless it is a minor change. I had the mazda remote start installed so as to keep the warranty as well as keep the car as "stock" as possible. This will help when you sell the car because hardly any mazda3's have remote starts installed.

 

Also if you install an aftermarket one, it tends to keep the value the same or lessen it because when they sell your car used they cant warrantee something aftermarket like that so they remove it...