So with the Alpine premium sound since there's an amp in the trunk I'm guessing the head unit has no power coming get out of it? Just line outs. Is that correct? So if the wires were cut from head unit to right before the amp you could then add an amp. Therefore bypassing the factory crossovers Right? Seems like the head unit might be good enough to use and keep the "stock"look in place. Then by adding a better amp and speakers your could improve your sound. Am I on track with this thought process?

 

The thought process is good, I'd find a reverse hookup for the amp out before cutting connectors, but I hate cutting connectors in general when doing anything electrical. I'm not sure if the head unit gives raw line out to the amp, i believe it uses a proprietary communication protocol to there, esp. with the alpine system.

May be able to find a converter online that converts said signal to line out, then use an aftermarket amp with the reverse hookup to feed power thru factory wiring to your new speakers.

 

So I just picked a stereo. Still not able to find an affordable one that I felt fit the look of the car, I just ended up choosing the Pioneer DEH-X6800BT. It was on sale during Amazons Prime day sale today, and I've got a similar one in one of my Subarus and I'm happy with how well that one integrates with my phone.

Now I just need to get the wiring harness adapter, but I'm having trouble locating one for these cars. Searching I've found ones listed for S & X types but not the XJR or XJ8.
I'm also wondering if it is possible to use the microphone built into the car with the stereo for bluetooth calls. Anyone hooked that up to an aftermarket stereo.

I'm going to figure out the steering wheel controls later, as I've discovered my steering wheel volume controls do not work (cruse buttons work just fine though). Any tips on troubleshooting that?

 

Look at the connectors for the front indicators they have Volkswagen Audi logos on.

I agree with the OP though, I don't understand why many after market stereo systems have to be lit up like Christmas trees and have buttons so small you need a toothpick to press them. A common thing I see on them is they are stuck on demo mode a lot as folk can't work out how to switch anything on or off with it! LOL.

 

What do you mean by the front indicators? When you say that I think turn signals and can't think what that has to do with the radio. What are you implying, no need to be cryptic.

 

Who's being cryptic? Indicators are what "Turn Signals" are called in the UK. It has nothing to do with the radio, I was merely leading off Highhorse's point about the Ford branding on the connectors.

 

What's interesting on the Ford vs Jaguar parts costs, when I had my Lincoln LS it shared lots with the S-Type and I found in most cases the S-Type part was cheaper.

 

Oh sorry, I thought you were talking about the radio adapter and mentioning one that would work without saying what it was.

Carry on...