Was the itemized list of costs from your actual sales contract that you signed, or was that from something unofficial that they gave you as part of the buying process? Because they can only hold you to what you signed, so hopefully you have the original sales contract. If your itemized numbers are correct, your remaining balance should be 41k, not 51k! That's a huge discrepancy. It's definitely not normal, and there aren't a lot of add-ons that could cause that, so if they're trying to tell you that's the bill, they either didn't give you the price they said they would, or they've sold you a more luxury model of the same car (or at least charged you for that).

By the way, since you're new to the USA, it's worth knowing that here we use commas (,) to separate thousands, and dots (.) to separate decimal values or cents. So your price would hopefully be 49,000 :).