The rule with finance is that the car cannot be more than 10 years old by the end of the term, so if your finance agreement runs for 5 years you cant but a car older than 5 years.
If you've been approved in one place then you will probably be approved elsewhere.
Go to your bank and ask them to beat your finance quote but for a personal loan. If its a loan then it isnt attached to the car and for that reason you can buy what you really want, for example an evo 7 or mk1 focus rs etc