I'm a dyed-in-the-wool Hamann guy. And I speak as someone who absolutely loves the look of a stock beast (so much so that I can't part with mine!). But a properly decked out Hamann car just seems to take it to the next level. Here I offer a brief study.
In photo 1, my stock beast...classy e39 lines: muscular and refined.
In photo 2, El Diablo...more of a wicked look. She has a Hamann front lip, Hamann side skirts, and Hamann rear bumper/diffuser (also Alpina deck spoiler and AC Schnitzer roof spoiler).
In photo 3, the two cars are shown side by side - a stock body vs. a 'body kitted' one. Somehow, my stock beast now looks rather, um, plain. Everything is relative I suppose.
Photos 4-7 are of two other cars I really admire. Ron Thomson's car (4-6) has some of the same Hamann pieces as Diablo, but a different rear diffuser and smaller deck spoiler. Btw, imho a roof spoiler really adds a nice touch in combination with other modifications. Photo 7 is of the legendary PhillyM5 car. Again, Hamann front lip (which he recently added). Side skirts are not Hamann.. not sure who makes them. Imho, adding a full front lip would look front-heavy without side skirts to carry the lower line around the car and complete the lower aero look.
I used to think there was no way you could improve upon the classy lines of the e39 M5. Now I'm crazy about the nasty look of many modded beasts on the board. Imho, it is possible to do some pretty significant esthetic mods to the e39 without looking ricey. I guess it is all about what you are trying to project.. muscular and refined, wicked, or somewhere in between.
Dave