A couple are repeats but yeah.
1) People who drive slow in the fucking fast lane.
2) People who take 2+ spots with a $500 car in a busy parking lot...
3) People who
ALWAYS have to one-up your story. URGHHHH.
4) Suppose you drive someone around A LOT then bitch when you (legitimately) forget you owe them ~20 bucks. (after spending 200+ on gas driving to mutual events...)
5) People who whip out their phone in the middle of a conversation to text their girlfriend, like holy FUCK it can wait until i'm done my sentence...
6) People who drive on bald tires because they're too cheap. (or summers in winter)
7) People who treat expensive cars like shit, WAAAY too long between oil changes etc
8) Possibly my biggest car related pet peeve... People who throw it in drive while still rolling backwards at ~2-5km/h, that clunking and the car jerking...
9) People who brag about how much they can drink.
10) People who tell you to change your lifestyle for whatever health reason, as they sit there chain smoking.
11) Compulsive liars. The type who when shown un-deniable proof still refuse to admit it.
12) The "i'm never wrong" people...
13) People who think Friday the 13'th is "bad"
14) Those douchebags who cut you off and go super slow in front.
15) People who act like they're experts but know shit all, (i.e politics)
16) Those assholes who scuff/try to eat in/generally dis-respect your car. I had an (ex) friend who actually tried to smoke in my car, then bitched when i yelled at him as he pulled his lighter and smokes out... I literally pulled over and kicked him out of the car.
17) People who refuse to listen to good advice, then once they've screwed up refuse to admit you were right.
/end rant