That's not a tip. It's a "processing fee" assessed by credit card companies (a revenue stream). The 3% charged on top of a large purchase like a vehicle goes to the payment processing provider (the credit card company). To cover the cost of professing fees, most dealerships often offer a cash discount (meaning they will quote a lower price if paid by check).
1. The guy who owns the dealership doesn't get the credit card fee
2. If they charge you extra for using a credit card, they're breaking even
3. If they _don't_ charge you extra for using a credit card, they're paying 3% of the purchase cost to the credit card company (so, $1,000+)
So yes, it's a dick move to pay via credit card for any purchase in the thousands of dollars, if you have the option to pay by check or debit card. I always offer to pay by check if I know the money for the CC will come out of their pocket.
Don't really care. It's not my responsibility as a customer to make assumptions about how businesses prefer to get paid. They can add surcharges or just not accept credit cards at all. As someone who has been making some large household purchases this summer, my experience is that it's perfectly ordinary and expected to pay by credit card.
I'd just add that I routinely book flights, hotels, and so forth in the thousands of dollars range on credit cards and I doubt they would want anything different as a payment type.
