iSimple - SoundByte Apple® iPod® Connection Kit for Select Vehicles (Basic Install Included) - ISHS71
Personally I like it, installed it today and works 100% with the factory radio. Cost is $199 vs the approx $500 I heard from the dealer.this also gives me the option to purchase the HD radio option which the factory option doesn't include. Install was only about 20 min.
Sorry it only works for the 08+ WRX and STI with factory radio or nav unit. They do have an aftermarket one as well that I have not used yet.