...here're a couple of my more interesting tales of underway woe:
1) The Pontiac Fiero was an almost entirely parts-bin car. Except for the body and the large visible chunks of the interior, nearly everything was sourced from extant GM vehicles: The front suspension came from the T-bodies (think "Chevette") and the rear suspension and drivetrain was basically the FWD X-body's (think "Citation") turned 180°. The parking brake handle came from the C4 Corvette, and was sandwiched between the driver's seat and the door.
To operate the parking brake, you'd raise the handle, which would ratchet the brakes on, and then lower it again so you could exit the vehicle without fouling your undercarriage on the brake lever. To take the parking brake off again, you'd pull the lever up, push the button on the end, and lower it. In other words, whether the brake was on or off, the lever was down; your only indication of the different status was the "BRAKE" idiot light on the dash.
You can see where I'm going with this, right?
I never actually used the parking brake, what with my car having the V-6 engine and a granny gearchanger. But apparently I messed around with it one day... Did you know that it was possible to disengage a Fiero's parking brake enough to turn the light off, but still have the brake slightly engaged? And that if you drive half a dozen miles or so down I-85 in Atlanta with a caliper dragging, you'll boil the brake fluid and be rewarded with an horrific smell and a pedal that goes to the floor?
Luckily I noticed on the interchange before my off-ramp, and between there and the Armour Drive traffic light at the bottom of the ramp, I was able to pump some life back into the system, but it was a pretty hair-raising experience.
2) The Honda 700 Interceptor had a hydraulic clutch. The lever was only attached to the bike by the pivot screw, since it just operated a piston on the master cylinder. Once upon a time, immortal in the way that only 20-year-olds can be, I was riding home from work at about... oh... 100mph or so, northbound on GA400 (easy to do during morning rush hour, since the northbound lanes were deserted and the southbound ones were a parking lot.) Tooling blissfully along, something twinkled briefly in my peripheral vision as it fell off the handlebar. It was the screw from the clutch lever.
Followed almost immediately by the departure of the lever itself.
In what remains to this day one of my more virtuoso performances at the helm of a motor vehicle, I somehow managed to drift across three lanes of light traffic, downshifting from 5th to Neutral without the clutch, and bring the bike to a halt on the shoulder of the road. I then had to detach myself from the bike, walk back, and dodge traffic to get my clutch lever, laying in the road out by the median. It was more of a hike than I expected; it takes a bit of road to coast down from the far side of the Ton.
A crude pivot was MacGyvered from a small twig of Georgia pine lying by the side of the road, and using this and a deathgrip to hold the lever on the bar, I rode to the Honda dealership for a replacement part, and all was well as ended well.