Can't help you with the racing belts, but I also found the "stock" setup is not very good. Agree the angles aren't great and I've had the passenger one not retract at all once and was a bit of a pain to get it working. I just put some universal retracting ones (shoulder and lap) in an older car (British car and belts from a British car company) that work very well. I'm going to look into putting a set like that in the 818 if I have any more issues with the stock ones.

Rick