Well, where I am at the moment is that I love my car (First car!) but I can't help buy keep looking at other cars, even made myself a shortlist and saved a few searches on Autotrader that I check every couple of weeks to see what has popped up and keep an eye on the average price on them.
The thing is that the cars I want (TT, C30 T5, 125i, 330i), will be about £12-15k there abouts, I will need to trade in mine and possibly take on a small loan agreement to get it. Currently it cost me nothing to run my car apart from the norm like tax, petrol and insurance. Nothing has broken (that isn't my fault - pothole) and passed the service and MOT with a clean bill of health. I did 9k miles last 12 months so what mpg it returns (40mpg) is more than acceptable.
I also can't help but to think I might resent a new car because of that, going from the 100% total ownership to "that car on the drive now cost me money every month" and the feeling that it isn't mine quite just yet, at least not for a few years. So I know it is too soon to change my car, at least logically speaking as it makes no sense in every way - financial, practicality, mechanically or even how the car looks as I do like it. The only reason I am looking is because I want to upgrade, that being better built quality, a little faster, quieter cabin and more toys. Things that isn't essential or necessary.
Or do I just keep it and buy a £6k Z4? Which will probably cost less than putting £15k into a single car.