Is anyone using an iPhone 4S with the Advanced App. Mode on the P8400BH? I noticed that the P8400BH doesn't include a GPS antenna like the AppRadio does.

Do the iOS GPS apps. still work well on the P8400BH even without the addon GPS antenna?

I have the 8400 with the CD-IU201s cable. I just installed it yesterday. Both MotionX GPS and google maps work perfectly. I dont know how well they would work with poor signal though.

I believe the iphone uses cell tower triangulation for a gps signal.