I know this is very off-topic but don't beat yourself up about making quick decisions like this that cut that kind of persistent, simmering rage out of your life.
We have enough of this stuff with people in our lives, often unavoidably, so letting appliances/devices/products cause it is not something we have to tolerate. If a _thing_ makes you feel unsatisfiable anger, get rid of it.
Isn't the correct term "vote with your wallet"? "voting with your feet" implies switching jobs or emigrating.
I couldn't get on with the thing, but I felt bad about selling it to anyone because the resonator was more trouble than it was worth. Some frustrations should not be sold on.
So I kept the very nice guitar case, and gave the guitar away to a talented, broke musician, who used its rather scratchy, broken sound for effect on a couple of recordings.
I could have sold it for a few quid but I have never regretted this; I turned my frustration at this thing into a gift and a bit of joy for someone else and then moved on.
Not something I'd recommend everyone does regularly, because if we all do it, it just prolongs poor product design by failing to reject it, but it helped this one time.
(It also taught me an important lesson about musical instruments; the next guitar I bought was better, but more basic in appearance and already scratched from the shop.)
I had a similar experience and called an attorney, who explained that, in the U.S., you can really only sue for any actual loss (whether to the vehicle or to you). If you weren't injured or killed, and didn't suffer extreme anxiety or something like that, then you suffered no real loss and really have nothing to sue over (unfortunately). You can't sue for what might have happened, only for what actually did. (You probably could have sued, at least in small claims, for the loss of use, cost of repairs, decrease in value, etc, if you wanted to take the time.)
With that said, you might have been able to get them to take it back under your state's lemon law, if you hadn't already sold it, but the lemon laws generally only cover multiple defects over a period of time anyway. :(