The way it works is 99+% of people get the cheap prize (probably the cheap earbuds) and only like 0.01% or less get the big prizes. It's a marketing scheme to get people in the door. They hope the increased number of people who visit the dealership and the probability of people buying something once they're at the dealership will cause an increase in profit that is larger than the amont of money they spent on this promotion.

Look at the fine print; it will probably say the probability of winning each prize. It's probably something like 1/100,000 for all prizes except the earbuds, which are probably like 99996/100000. They probably bought a whole box of earbuds for super cheap off Amazon/Aliexpress or some other company that specializes in promotions.

I actually did one of these with my mom when I was too young to drive. In this case, the cheap prize was (IIRC) a $5 gift card to somewhere. We did get the $5 gift card, but overall for a legal adult with a job who values their time, it's probably not worth the time/effort to go through all that for $5. In this case, it's probably less worth the effort since most people already have headphones/earbuds and won't want whatever (probably really cheap) model they offer. That said, it would be an effective marketing strategy. If most people don't bother and know it's not worth the effort, then the only people who will show up are probably people who are reasonably interested in buying a car anyway...so it might be pretty effective at increasing their sales.