I had (and still have) the same problem with my car. I'm convinced that it has everything to do with the paint job. (bright orange) If it came in a low-maintenance color like... silver or what have you, my car would probably look like s*** right now. (afterall, I've had it for over 4 years.) instead, it's immaculate inside and out.
Granted, I don't have kids (yet) so I'm coming from a different perspective. Even still, though black does reflect dirt more than other colors... your car getting dirty isn't the end of the world.
Don't take any offense but... when i see a MS3.. all I see is a Mazda 3 wagon. The same couldn't be said back in the day between a regular protege and an MSP. For this reason, and others, I doubt I'd be the madman I am detailing my car every weekend if I owned an MS3. My perception is that it's more of a regular, mainstream type of car.
now... if it came in bright orange, that... would be another story!
All I know is... unless you find a sucker, there's no way you're getting $23k for this car. That's what they sticker for new! LOL As I said before... if someone is going to compromise and get a slightly used vehicle, it better be one hell of a deal. If it's close... even by a couple grand, I think most people (interested in a performance oriented car like this) are going to go new.
Just keep the car man! Next to the RX-7/8, it's probably Mazda's best effort to date. Do what I do/did whenever I'm thinking about selling my car. go read the the reviews! It trounces the competition and receives praise from all types. So what if it gets a little dirty? It'll wash off! Kids mess it up? Big deal... that's what vacuums are for. Good luck
