I'm the current custodian of a 2001 XKR convertible. It's a blast to drive, but as someone who has restored jeeps and worked on all sorts of vehicles, I'll say my first impression is that Jags are, uh, quirky. This one has long had the passenger seat tilted way back. Why? Because the power tilt forward doesn't work. Fast forward to two days ago, when adjustment of the driver's seat left it tilted so close to the wheel the car was un-drivable. Arg! Thanks to insights on this site and others, I quickly narrowed down the likely suspect to the seat control module. This is an old school circuit board with traces (conductors) really near the edge that corrode out. Other posts will tell you there's literally a guy named Darrell who fixes them. Well I didn't have time for that, so I pull the seat, open it up, and yikes! Frame looks to be hand-brazed, there's about 17 motors and jackscrews in there, and enough conductors for a space shuttle. However I was able to mechanically untilt the seat by removing the plastic covers at the ends, removing the round clip (it'll break) from the seat tilt shaft (it goes straight across the bottom of the seatback) on the motor end, and driving the shaft out of the motor gearbox. You can then turn the splined actuator with a screwdriver while turning the other end of the shaft to move the seat tilt. Then push the shaft back into place. You may have to pull the wire clip and rotate a bit to get everything to line back up.
But then I hit on a better idea. The seat modules are interchangeable. So...if you remove the two 10mm nuts that hold the module to the seat and modify the mounting with some velcro (or zip ties) to hold the seat module in place, you can swap them. So if you have only one working module (or in my case, to complimentarily broken modules, you just have to unplug the modules (2-3 connectors each) and swap 'em, to get you out of trouble.