Strongman competitors are incredibly creative. They have to be. Imagine playing in a sport where the implements are constantly changing... that is strongman. It's one of the reasons why the limiting factor to strongman training is the equipment. Don't have Atlas Stones? Use an Elite Stone Trainer. No Husafell stones? This one can be filled with water.
Are you trying to replicate a car squat? Maybe a hack squat? Looking for better leg development? The Car Squat Simulator could be the answer. EliteFTS™ Athlete and Pro Strongman Andy Deck demonstrates:
The Car Squat Simulator requires a little set up, however it's all performed with items you most likely already have access to. You'll need 2 landmines, 3 barbells, 4 light weights (5lb or 10lbs), 2 collars (Croc Lock™ Collars are HIGHLY recommended) and a squat rack with safety pins.
The set up is pretty straight forward, however make sure you attach the barbells correctly. You want to slide a light plate on the landmined barbell, then the squatting barbell should run underneath the landmined barbell. After that you slide another plate on the landmined barbell and finally top it off with a collar, effectively sandwiching the squatting barbell underneath the landmined barbells.