And if you buy a nice car with $10K in BTC, the car dealer would still have to report you as if you bought it with cash. I'm not saying it's right, but I don't see how it is a narrow attack on transacting in bitcoin versus transacting in cash.
Unless you buy from a car dealer that doesn't. I see you like trolling gov't fear around here. What exactly do you do for a living? Just post shit for the IRS?
The car dealership must file a report with FinCEN whether you pay by BitPay or bankwire. I don't think this has anything to do with the IRS, however. And having a report filed doesn't mean you've done anything wrong. Here is the quote from BCB:
If I just send right to the dealers bitcoin address - no Bitpay is required, and so no reporting is required. I know of a couple dealers who would do that and never say a word about it.