Consumer Reports warns of a potential problem with as many as 30 million rubber replacement valve stems manufactured in China for NC-based Dill Air Control Products and sold after mid-2006. While a federal recall hasn't yet been issued, NHTSA has opened an investigation after a Florida man died following a blowout and flip allegedly caused by one of the defective valve stems. Yes, it was a Ford Explorer. So, how do you know if you have one of the millions of potentially deadly valve stems on your car? Identifying a defective valve stem is simple: Dismount each tire from its rim and check. That's right, folks: There's no outward marking to identify the defective valve stems, nor was any tracking system in place to determine who may or may not have received one. So, if you're part of the at-risk group, you probably want to keep both hands on the wheel until NHTSA sorts all this out. [Consumer Reports; Photo and tons of great valve stem info at Techno-Fandom.org]