Pierre I'm looking for a helmet too. Same problem with cost.
My last helmet--outdated now==bought at a motorcycle shop. Typically they're Snell and DOT approved for motorcycles only. Car approval is another category.
We did SOLO racing with PITL here in Mississauga. They accepted motorcycle helmets and didn't require themore expensive helmet for car racing. YMMV
What do Vette owners use at Mosport?
FWIW--for car racing (SNELL and DOT) Mantis Racing Oakville? Burlington?, and there's a distributor/sales place (can't remember name) in Newmarket that distributes Bell Helmets.
Regards,
DaveL
ps difference--someone more knowledgable? I believe that MC helmets are only required to handle 1 major impact. Car racing helmets--multiple impacts?