An easy way to get Wipefest, Truck Stop and Smash Hit all in one go!
Local match, one controller per team. First round, both teams kill themselves (just stand on the fire until incap X 3, cpus will help you up)
Controller getting achievements should play through normally. make sure all 4 surivors, or close enough, get into the rescue vehicle.
The one not getting the achievement, playthrough up to the hoard like normal. die as the first tank. then, get yourself killed as a boomer or smoker. see what you will spawn as next. is it is a hunter, get yourself killed as that, and then the next infected also (back until the spawn should be what it was before the hunter. then, die as second tank.
when the vehicle opens, the cpus will run to it. before you are a tank, you should spawn as that hunter. go near the human player. THE HUMAN PLAYER SHOULD BE NEAR THE CAR AT THE BACK OF THE AREA! When you become the tank, the hunter should pounce the human (if you didn't do it in time before you became tank).
The survivors will all rush to save the human player. they will all stand around (after killing hunter) to help human player up, by at which time, you should be near enough to incap all three survivors (using the car). You should instantly get 'Wipefest' (and 'All 4 Dead' if you don't have it, assuming they helped up the human player). Shortly after, 'Truck Stop' should pop, when the scores show up. 'Smash Hit' tends not to pop until the match has ended.
Local Match, 2 players.
die in 1st round
Achi controller finish round as humans
non achi controller finish round up to 2nd tank
stand near car at back, get incapped by hunter after vehicle is open
as tank, hit car at all 4 survivors, ding, 3 achievements!