I feel this debate is a bit like when someone comes in to slag off RPIs - one sided. So, as a car lover I'm going to issue some defensive points.
I owned a Saxo VTR back in 2003, and it was modified with a custom built sports exhaust which ended in a 5 inch exit. Yes it was loud, but that is because the exhaust system was no longer stifling power by destroying the sound an engine naturally makes. It was made at Welwyn Garden City and cost me over £400! It conformed to all road limits on noise regulations, and added an extra few bhp, along with better responsiveness, and a crisp rally style 'brap-brap-brap' on downshifts. The noise can be about performance, after all sports cars are all extremely loud because they want the maximum performance out of an engine. It was also fitted with a sports induction kit made by Pipercross I think, and this helped liberate a few more bhp, along with yet more sharpening of the engines throttle response, and on a cold day it would snort like Amy Winehouse!
The body remained standard, as did the suspension and window tints. I changed the wheels to items of the same size but much lighter weight, as reducing the unsprung weight improves handling greatly. NO NEON LIGHTS! I had a personalised registration featuring VTR which I never misrepresented and used the standard typeface for. I never drove with the fog lights on, except when the fog warranted it, and I always used my indicators (I'm looking at the BMW driver above for those last three points - after all, if you can generalise about people modifying a car, I can definitely do it about BMW drivers). Because of visibilty driving at night (that'll be the shift work) and because it helped when tooling down country lanes I knew, I fitted a bank of 4 rally spec Hella spotlights that were activated by the main beam of the cars headlights.
Whilst 15 bhp may not sound like much, you have to bear in mind the standard car was 100bhp, and the kerb weight was 890kg. So I went from 116 bhp/tom to 134bhp/ton.