The occupants are held in place with fixed bucket seats. A roll bar was welded to the chassis to prevent the occupants from becoming a foot shorter in the event of a roll over.
Looking a bit closer, you can see that the unibody has been stitch welded. Older cars tend to be more flexy, so this stitch welding should really help firm things up.
The wide and sticky Nitto NT01s are mounted on fat lip Volks. From the engine to suspension to tires, I bet this car is an absolute blast to drive.
This BMW is sporting some old school European touring car wheels wrapped in Achilles slicks.
Track cars need cooling, so you can see the array of heat exchangers behind the front opening and a lower bumper opening fitted with a brake cooling duct.
Here is the back side of the duct dumping air towards the front brakes.