the structure of the conditional you need is past in the first part and then present perfect "if I had the money I would buy you a car" bacause you don't really have the money.. if you had it, you should say, "I have the money, so I'll buy you a car". besides your sentence is wrong because did only goes in negative and interrogative sentences, in the affirmative ones you need the verb in past. I hope it'll be useful !!! byee!