Ohh i'd see a doctor about that burning sensation... could be a symptom of something serious... of course i'm not being serious. From what i can tell (and not knowing the model year of the car) from the letter, you're expecting 379.41 plus 500.00 because some plastic bag you drove over stuck to the hot bits of your cars underside...causing a burning sensation and fumes? And you got a complementary socket wrench alreday? I'd take away about 800 bucks and some change from your expectations then subtract 79.00 for asking for your money back when you got your car fixed and didn't check the work before leaving.
Nice try though.