Just wondering if anyone knew the extent of the modifications neccessary on the AP1 to fit the AP2 headrest speakers?..... Thanks.

 

They should be a complete bolt in. Just wiring would be the harder part.

However, I strongly suggest getting the headrest speakers for the AP1 seats. I have them and they work great. I have sat in cars with the ap2 rear speakers and you can barely hear them, even with adjust the radio controls. With my headrest speakers they are super loud.