So you spent $ 2400.00 / year on maintenance/repairs, on an 18 year old car.
Ha, I see people spending that kind of money on a 3-4 year old car.
By my calculations, that's about 5 months worth of payments on a new one.
I don't have a degree in economics, but find it cheaper to maintain & repair, then purchasing new vehicles periodically ( maintenance, depreciation, higher insurance costs, etc, etc.).