Personally, I've never taken advantage of any of the road side car detailing businesses that pop up during the warmer months, like the one shown here. Don't get me wrong, I'd love to look good down the road. I'm just a bit persnickety about who lays hands on my vehicle, is all. Consequently, my car is pretty much always a dirty mess until those rare occasions I get around to cleaning it myself... That said, my wife did try one of these places once, and immediately afterwards the headliner in her sweet VW GTI started to drop. I guess they used a cleaner that was a bit too strong in the solvent department. Caveat emptor. Kind of how we operate these days.
