I just successfully transplanted a very good, working quarter window and regulator from the parts XK8 into the XKR. The two removals and one install took about 5 hours in total, but I took my time. The PDF in the stickies was of immense help, but there were a couple things that complicated my issues.

• The torx screws that held the trim on were immensely hard to remove and install. I ended up cutting down an allen key to about a 3/4" right angle so i could get leverage on them. The PDF author gripped the outside with pliers, I didn't have any needlenose handy so I improvised.
• Getting the assembly out of the parts car did indeed require removal of the three bolts which attach the left side of the convertible top hydraulic assembly, for both removal and installation. Even with that I had to put some leverage on the convertible assembly to get enough clearance. Getting the convertibly top assembly realigned was challenging, but the lowest bolt is not a hole but a rest, and you can put the bolt in, then plop the assembly on the lowest bolt. This then allows you to manipulate the assembly to attach the other two bolts, which are holes.
• If your window assembly does not allow the window to be pulled up manually, it will be a huge challenge to remove. Mine was jammed, and the cable was snarled. I solved this problem by literally removing the motor and cable assembly from the regulator frame, and removed it via the hole in the rain shield. This allowed for easy removal of the broken assembly remnants via the top. This method does not require the removal of the convertible top bolts, but you'll need to remove them anyway to get the new apparatus in.

My XKR rewarded me when I went to go troubleshoot why my convertible top switch didn't work, and found that the harness had just come off the switch. This was a very good feeling to have a 20 second job after such an afternoon ordeal. Now, too, I have extra regulators for both sides. I had bought a salvage one before I got this parts XK8, so in the labeled bin and onto the shelf they go.

 

Yes, if the window is stuck part way down, extracting the assembly becomes all that more challenging. Congrats on your success!

 

I noted today that when the quarter window is up, I have about a 1/2" gap between that and the passenger window. Oops. I am hoping that the adjustment doesn't require complete removal of the stabilizer, subwoofer etc...

 

The top travel stop may need adjustment. I'm pretty sure the sub has to come out to get to it. Looking back at my pix, I note that I connected the power to the replacement and ran the window up and down to make sure it aligned before I reinstalled the sub, brace, etc.

 

Well on the "Bright" side, the previous plonker that had this car mangled that side trim quite badly, so it pops in and out without having to remove the seat. I have another whole piece from the parts XK8 (thankfully the same color interior!), which I'll replace at some point.

 

I may be in the market for a used RH cat. I'll know more in a couple of weeks. If your parts car still has intact ones, and you're willing to part with it, I can DM you for more information.

 

PS - I re-read my initial response and it sounded like I might have been criticizing, and I didn't mean for it to sound that way. I just meant that I tested it first because it looked like the adjustment bolts were inaccessible after the sub was reinstalled.

 

All good, I didn't take it as such. Speaking of criticism, whoever designed that whole window regulator area on the car must have been of the "no user serviceable parts inside" school of engineering.