Got a dash alert that the right rear tire was down to 35 lbs in my x. Took a look and saw a roofing nail in the tread.
Pressure stayed stable at 35 lbs, so I drove over to a nearby tire shop.
They had a little trouble getting the chrome caps off before using an air wrench to remove the wheel nuts.
First time they had seen a continental tire with the foam installed. They scraped it away and installed a cool looking plug with a pointed needle on one end and a big blob of sealing material at the other. They drilled out the nail hole to make a calibrated hole before inserting the plug.
Plug did not seal well, so they removed it, used a air driven brurr scraper to get down to the bare rubber and provide a rough surface for the plug material to seal.
That did the trick. Been driving several days on it and it is holding pressure stable.
If you get a flat, mention that they need to get rid of 100% on the foam material where the plug will sit in order to get good adhesion.
Charged me $35.00. Know that some shops will fix them for free, but it happened on a Sunday afternoon when few shops were open. Took about an hour. Was happy they were open and consider it good value.
Tires are now about 50% worn at 22,000 miles. Will get a fresh set next year.