Goat Simulator

Head over to the drive in theater. If you are looking at the BAAA machine at the start it will be Northwest of you. Directions are difficult since there is no true map to work with. Once you are at the drive in, run up to a car that is in the parking lot of the drive in and press . Press to change characters and take this character up to the car and press . Repeat for the last two characters and after a few moments of all four characters being in the car your achievement should pop.

JayD101 may have easier directions to the drive in than mine.
" If North is the BAA machine it depends where you are when you look at it to where North West will be. If I sit right in front of it and look directly at the machine the movie theatre is actually very close and dead west (left 90 degrees). So when I went Northwest I got lost lol! So just to help:

If you exit under the zoo sign, turn left and go between the 2 torches, follow the path past the crashed plane on your right and go between the 2 rocky formations to another set of torches. There you will see in front of you a set of start/finish signs and beyond a much bigger billboard looking type thing. That is the drive in. Keep following the torch path under that "Start" sign and you will be there!"

Thanks Jay

For the Goatfellas achievement, you need to get all of the animals in the payday DLC into the cinema car park/ You can find the car park by heading towards the city buildings and take your first left you will then see a large screen in front of you, if your lucky 4+cards will already be there. If there are 4 cars just get into them one at a time by pressing y/triangle. one all your goats are in your achievement will pop. If there aren't 4 cars there don't worry you just have to steal a car and drive into the car park and the achievement will still pop.

If you are still having trouble or would like to see where the cinema is use my video guide below

From the very start (the zoo) go over the hill with the cannon on it to the left. Past the racing "START" flag with two torches will be an open drive-in movie theater with 3-4 cars. Take every animal and put them in one car