It's a very personal thing. Enjoy your car the way you like!
Cars (esp the "sporting" types) tend to go through life-stages.
When new they are mostly kept very close to original, probably as much for warranty-void concerns as much as anything.
As they get older, esp 5 - 15 years, they drop in value & folks who couldn't afford them new get them & often do them up. Go-faster bits can take a while to get onto the market & are more plentiful (& cheaper) when the car is a few years old. Warranty-voiding is no longer a problem & adding stuff to the car usually won't kill the resale value (although no-one ever gets back what they spend on extras, IMHO). Most MR2s, Skylines, WRXs, etc currently fall into this bracket.
After about 15-20 years though, it's funny how the pendulum starts to come back the other way. People seeking out interesting "old" cars (eg RX7, 240Z, plus the "classic" marques) often want them in original condition (ie: "As it would have been if I could have afforded it all those years ago"). Supersized wings, pipes, turbo add-ons, etc can start looking out of place & make a big dent in the car's resale value.
For those of us who are into appreciating "classic" cars, any car with added mods is probably looked at slightly circumspectly, as one day it may be a classic & all those bits should come back off. Maybe that explains some of the responses on this topic by FFers.