i see...sorry to have wronged youbut i guess your wordings made
us misunderstand.
Well, here are some suggestions. You mentioned that you are driving
a 2 yr old car which u think is horrible..Since its pretty new, why
the sudden change of mindset? I mean you couldnt have felt it was
horrible and bought it two years ago right?
Well lets say it was a mistake. On choosing your next car, do a
through research before deciding on one. Best if you can find a
friend who can let you test drive it or go down to the show room to
test drive it.
When test driving the showroom car, DO NOT be modest. It is not a
test drive car for nothing. just whack it hard to find out its
maximum performance and see if it suits you well. what i mean in
suiting you well are not the power figures but the how well the car
balances and handles the power that its engines curns out. You will
love your car when you know you are able to control it accurately
and precisely. almost like when car and driver is one. haha.

On your current car, minor mods should be no problem when it comes
to selling car. For example, Cold Air Intake, Bigger rims
etc.
Bigger wheels are said to worsen your FC as the tire is now broader
and has more contact point with the road, thus giving rise to added
friction. You engine has to burn petrol to over come this extra
friction. However, pple do feel that a right sized rim will improe
handling of the car.
For mods that are illegal, not only will you have problems selling
them but it would be difficult to pass inspection of the car. An
example would be adding a turbo to your car.
However, the easy solution would be to remove illegal mods before
selling the car and hope that the inspection pple like to drink
coffee cos you will be paying them coffee money.
I hope this has helped you? if not feel free to ask more questions
and i try to help you again.
Once again, i apologise for misunderstanding your intentions.