Somewhat more esoteric, and much more expensive, was a chap I know who rallied a Lancia Stratos quite a long time after it's heyday. It was a wonderful thing to see (and hear), but he failed to finish events due to mechanical failure more often than he got to the final time control. The failure was almost always the gearbox, and happened on right-hand bends (I think - it's been a while!) Eventually, the owner and his service chief went to Italy to track down a long-retired drive-train engineer from the Stratos factory team. The conversation went something like, "What gear are you in when it happens?"
"Hmmmmm, changing from third into second. Why? " (again, the specifics might be different).
"Ah, yes, that has always been the case with the Stratos. [Long discussion about why it happens, which I can't remember.]"
"Really? Why isn't it documented?"
"Because it kept people who bought them coming back for new gearboxes."
"OK, so what did your team do to cure it?"
"We told our drivers not to change from third to second in the middle of a right-hand bend..."