In this morning's Star Tribune there was a story about how two people in Minnesota died this past weekend in ATV accidents. One woman was killed when the ATV she was riding on (with three other people, including two children) flipped over. The other person, a 16-year-old boy, was killed when his ATV flipped over after getting a flat tire, pinning him underneath.
The Attorney General of Texas referred to ATVs as "rolling death machines." This was back in the 1980s when the three wheeled versions were more popular. Wisely the manufacturers have essentially remove those from the market. The four wheeled versions are a bit more stable, but still incredibly dangerous to ride. The bigger they are the heavier they are, and when they flip over the results can be devastating.
The manufacturers have done a great job of protecting themselves from liability. The ATVs themselves as well as the owners manuals are plastered with warning labels about not carrying passengers, riding with a helmet and protective gear, never driving them on paved roads, etc., etc., etc. Basically, if you are the owner of the machine you are responsible for your own injuries.
Passengers might have a viable case, but it's probably against the owner rather than the manufacturer. And most homeowners policies have an exclusion for ATVs unless the homeowner has purchased a separate rider, for which they have to pay extra.
Without homeowners insurance coverage, collectibility of any judgment becomes problematical.
A lawsuit against the manufacturer is a possibility but they tend to be very, very expensive cases to get to trial. A law firm might have to spend $200,000 on experts before the case was over, which means that cases like this are not going to be taken unless the damages are so extensive that the eventual payout is worth the investment in time and money. A friend of mine in Arizona, a very experienced trial lawyer, has stated that product liability cases like this are only worth taking on if the plaintiff is dead or wishes he was.