At work we use some really strong epoxy to patch and glue furniture pieces together. This stuff is extremely powerful and sets up as hard as concrete in a few minutes. I guess just about any epoxy you found at the hardware store would work about the same, but this is the stuff I'm familiar with.
I'm sure most people know how to use epoxy but for the few who haven't messed with it, this is what it does. You mix equal parts of A and B and then use that mixture to attach things together. It works with just about anything - wood, metal, plastic, concrete, etc... You must work fast because after about 1 minute a chemical reaction occurs. It heats up and begins to set and become hard. 1st it's only as hard as rubbery plastic and if you hurry you can carve off bumps with a chisel. After another minute though, forget it. You might as well try carving a piece of granite.
I was wondering if Part A was applied to the brake pedal of a car, and Part B was applied to the gas pedal how that would pan out. It seems like as the driver did his or her natural driving routine, their foot would move back and forth and unknowingly mix the 2 parts of epoxy. At some point it seems like it would finally set up, and their foot would either be stuck to one pedal or the other. I suspect having one's foot bonded to either pedal would make it difficult to drive.
A long highway drive would probably result in the foot stuck to the gas pedal. This would be startling to the driver and potentially dangerous, but a quick thinker could use their left foot to push the brake.
An inner city drive with lots of stop lights seems like it would be more likely to result in a foot being stuck to the brake. That would be worse, I think. The driver would be cross-legged if he attempted to use his other foot to give the car some gas. (Although I don't know why you'd want to give it any gas at that point.)
It could have even more horrible results with motorcycles. There's all that right foot gear-shifting action going on. Also there's the brake and clutch squeezing. Each time one was squeezed it could be pushing 2 compounds together.
Again, I'll never actually do this! I think the idea could be useful in a comic strip or a screenplay if I ever need to somehow cause driving trouble for a character.