This morning, as every morning, right after I started my car, the TPMS warning light went on. I have grown used to this since it happens everyday and then disappears after about 10 minutes of driving. The warning usually shows the front passenger tire but often rotates to others. Today, it showed driver's side rear. I didn't think much of the fact that it stayed on through an hour's worth of driving, I had checked my air pressure on all 4 tires a couple of days ago. But when I got off the freeway, I stopped and checked the driver's side rear and was shocked to find it didn't even have 10psi. I had driven more than 30 miles on an essentially flat tire without feeling any difference. I stopped into a gas station and filled the tire to 45psi figuring that I had a nail, would lose some air, and I still had 30 miles to drive back. On my way back I stopped at a tire store to have them remove the tire and nail, and patch whatever hole there might be.

After removing 4 of the lugnuts, the fifth would not come off as the top of the two piece nut became disattached and spun around without loosening the nut. The tire store could not get it off, put my other nuts back on, and I drove onto my regular mechanic. With some effort, they got it off, but found no nails. Soaping around the wheels we discovered a hairline crack on the inside of the rim, right at the bead of the tire, exactly as happened to my other rear wheel two weeks ago. A quick trip to the welder and the wheel was back on and repaired.

This is one of the problems of having a car that has false warnings all of the time, the one time it's real, you don't believe it.

Secondly, those stupid 2 piece lugnuts will be replaced this week as I've had problems with them before. (anyone have some replacement suggestions?)

Third and finally, 2 cracked rims in 2 weeks, is this a trend?

I bought these on eBay after experiencing the same result as you with the two piece OEM ones. No affiliation just a happy user of those lugs... look to see if other sellers might have a better deals but the product is excellent IMHO.

Sorry about your rim

20 Gorilla Jaguar 12x1 5 OE Stock Factory Wheels Rims Mag Lug Nuts Chrome | eBay

Assume it happened on the '10 XKR with 20" wheels? Those tire sidewalls are just too short to absorb normal broken pavement variations. I'd gladly switch to 18" wheels and the corresponding 1" taller sidewalls that would eliminate most of such damage, provide noticeably better ride and still good handling.

Albert,
You're right, of course. If they hadn't come with the car, the standard 19"rims would have been my choice, a balance between the large sidewall of the 18" and the miniscule one of the 20" while still looking proportional to the wheel arch.

I have had plenty of bent rims. Sometimes they cause an air leak but mostly just vibrations in the wheel. I have the tire warning message too. I have brought it to the dealer twice to fix with no luck. I will be trying a different dealer with better service techs. Once I got faked out with the sensor when it was real and ended up ruining a rear tire by driving on it flat. Funny how its hard to notice while driving. I had the 2 piece lug nut separate too What a pain. The road side service couldn't remove it so it had to be towed to the dealer.

rfr66,
I had all of those things happen last week. Ordering the Gorilla lug nut replacements tonight.

The gorilla nuts are chrome and the 2 piece ones seem more of the match to the paint color of the wheels. Let me know if you think the chrome will look right

I'm going to paint them.