yes i will be doing the bypass, just wondering if a 4 pin relay will work the same as a 5 pin relay, the 4200 has an sd slot, navigation port, and i wanna say it has the slide effect like the iphone and the ipod interfaces are better and the 4200 has RDS, nick you should check on ebay and other places for the harnesses, i know ive seen the steering wheel interface for $40 on ebay and the gmos goes for about $60