will this apple car play pioneer work with our x308? i'm wondering wiring and fitment wise.

 

Fitment will, since it's a shallow depth. You'll have to modify an aftermarket faceplate opening to take the double din. Wiring will be another story though, as they don't have a plug-n-play wiring harness. So it'll depend on which model X308 you have with or without premium sound, and the like, but plan on pretty much wiring each speaker directly

 

Yes they all pretty much "fit" it depends on how much modification & work one wants to do lol.

 

Does it wire directly to the speakers or connect to an existing head unit via USB or another adapter? I doubt this will connect to the stock head unit and even if it did the sound would be junk by today's standards.

If your Jaguar has the standard sound system (no subwoofer on the rear shelf) then the speaker wires run directly to the dash head unit so easy conversion to aftermarket. If you have the premium sound system then the speaker wires terminate at the amp above the CD changer in the trunk which is great if you want to install an aftermarket amp and run RCA cables to the dash. A pain if you just want a dash unit as you will need to run wires back to the head unit from the trunk.

I know there is a great single DIN adapter kit out there that looks great and comes with wiring diagrams for both the premium and standard sound systems. I have installed three with little headache.