I have been toying with the idea of driving from Houston to Chicago and drive the "Old Route 66" to San Diego, has anyone done this and is this a good or bad idea to take this route in a Jaguar XKR? This is on my "bucket list" but I don't want to destroy my car in the process.

 

I drove parts of the old 66 highway back in the late 50s and early 60s when I worked at Edwards AFB and had family and school in Texas. I do know that there are only parts of the old road still useable. My memory tells me the road was not that great when it was the major route in my day. Today those sections useable would probably be pretty bad. But it would sure be fun to try. Keep us informed if you do it. Would really like to hear about your experience.

 

There are only a few sections of the original road left, but they are driveable with care, here's a pic from a couple of years ago.
Some sections were more like a dirt road than this part.