On some 05+ 5MT vehicles the cruise control will randomly turn off, usually after ~30 minutes or so. You can see why here:
This is how you can fix it:
1) Jack up the car, throw a stand under it (it's always a pain when you drop a car on yourself, so the stand is a good thing)
2) Find the sensor, it's the one furthest to the back:
3) Unplug the connector, it's red in my car:
4) Remove sensor, it's somewhere in the 19-21mm range, i just used an adjustable wrench, you can get to it from 'above'ish the transmission mount, because if you try to get to it from below you run into the transmission housing w/ the wrench.
5) Make washer thinner, file it, turn it on a lathe, sand it (it would take forever), buy a new one that's thinner...
I actually found the file worked the best, couldn't get a good grip on it in the lathe...
6) Install back in car
I looked on mcmaster, didn't see anything the correct size..
It looks like the 16mm one MIGHT work.. but you'd need to buy 10 of them to find out
The washer i took out, prior to 'modification' had the following specs:
I filed it down to 1.285mm (~0.0505")