This is why many articles and videos about purchasing vehicle mention to always negotiate the price and never get into a discussion about how much you can afford in monthly payments. If you tell them you can do $500 a month it is almost a guarantee they will make a $450 a month vehicle cost you $500 a month, or persuade you to spend just a little more by saying something like, $530 month is ONLY $30 more a month." Or, they will increase the cost of the vehicle and add a year to the loan to bring the monthly payment back down to $500, and if extending the loan out another year brings the payment below $500 they will add a 12-month oil change, filter, and 101 point inspection service plan to bring your payments back up to $500 a month.
Let me repeat myself.....never ever negotiate a vehicle purchase based on monthly payments. I think every consumer program, every car enthusiast program on television, every auto magazine, and that section about cars that newspapers used to publish every Saturday has mentioned this over and over. Unfortunately, these things aren't in front of consumers like they used to be and it doesn't take long for consumers to forget about sales tactics and manipulation. This is also the reason so many of these publications recommended getting pre-approved financing through your bank or credit union and making sure the sales people at the dealership are aware of this. They will still try to get you to use their financing, but if you are firm about it they will back down and just try to sell the vehicle.
Another thought: An article about this in the Tech Library might help someone avoid this mistake in the future. This is really something that should be in the resources section of an automotive forum.
And this is how they get $15,000 over MSRP. $15,000 is a lot, but at $84 a month it doesn't seem like that much if it is spread out over a 7 year loan. And if you don't watch them they will add something to make it come to $99 a month and tell you it's still less than $100 a month extra.