Everything.
I have replaced everything from the engine to the metal.
But I had the time and money to do so.
I love my honda, which is why I wanted to make her run right. I restored the car to better than former glory with up grading everything or fixing everything. I have to sell it because I can't afford to keep two cars right now. But I made my car look stock, while upgrading everything. Not a sleeper car, I must have got pulled over one or twice a week not because of my driving, but because I was going the speed limit in a honda prelude.
It handles like you wouldn't believe.
It has more power than my v6.
I created new seat mounts because I found the seats were too low.
Yes, I am a girl. Yes, I did most of the work myself. I know more about cars from getting under the hood of my prelude than I did from watching my father work on his cars. Honda Preludes are really easy to work on, if you know how to treat them right.
This is the author again. I just wanted to add that the work on my prelude didn't "need" to be done, but because I had the time and energy and money to do it, everything was done.