You can also buy the 4D objects for $100k each from the dimensional traveler. He appears in the first island near your basement apartment (in the bottom left of the 1st island) and the casino at different times
Mobius Strip 1 : StickRPG2 – Get three coca. – Give them all to the police officer standing in the middle of the police station. – He’ll give you a Mobius strip and a lot of good karma. Doing this will make the broski disappear.
Mobius Strip 2: Stick RPG 2 – Go to the club at night with high strength and challenge the broski with the big orange head at the bar (first room when you enter the club) to an arm wrestle. You should beat him and get the mobius strip. Doing this will make the police officer go away.
Klein Bottle 1: StickRPG2 Give the addict near the apartments at night a lot of Coca. You can get one from the screwdriver quest. You’ll get a Klein Bottle and negative karma.
Klein Bottle 2: Stick RPG 2 Get the painkillers at Wally Mart. Go find the infamous goth kid. He’s near your basement apartment in the evening. Give him the pain killers. Get the squeegee. Take the squeegee to the squeegee kid, he’s in between all the buildings near the club in the third island. You’ll get a Klein bottle and positive karma.