Cash is still fairly common, and manufacturer rebates are basically not a thing. If they were, you'd send them an account number (IBAN = bank ID + account number at bank) to transfer the money to.
In fairness, manufacturer rebates have pretty much (mercifully) disappeared in the US as well as they were basically a scheme to mentally make you account for a lower price you wouldn't end up being rebated for various reasons.
In fairness, manufacturer rebates have pretty much (mercifully) disappeared in the US as well as they were basically a scheme to mentally make you account for a lower price you wouldn't end up being rebated for various reasons.