Here are the modifications I have done to GBMINI since I bought it (click on highlighted areas of the pictures, or scroll down):
GBMINI April 20, 2003

Painted Roof Chrome Grille Driving Lights Driving Lights Painted Body Trim and Aero Kit John Cooper Signature Decals GreenStuff Brake Pads Aero Kit Front Plate Bracket

Painted Wheel arch & bumper trim, and aero kit side skirts
When I owned my MINI Cooper, I found that the black plastic trim around the wheels collected wax and greyed easily; it was a major pain to keep it black. I also did not much like the look of the black plastic against the Indi Blue; so I decided to have all the trim sanded and painted. MINI Peabody arranged this, sending all the trim to Sublime Restorations when the car was delivered. The side skirts were replaced with those from the aero kit - not only do they look better with the fake air intake, but since they are already prepared for painting, using them is less expensive than sanding the stock sill pieces!
The lower edges of the front bumper, and the rear wheel arches, are suffering from a number of paint chips from flying stones - I notice them every time I wash the car, but I don't think most people would notice. If I was doing it again, I might consider having a protective film put over the "sensitive" parts of the car!

Painted Union Jack flag on roof
When I ordered my MCS I planned to put a fullsize Union Jack flag on the roof - indicating both that the car and I originated in England. So I ordered the car with a white roof and no sunroof.
I did not want the official MINI decal, since it does not extend to the edges of the roof. Instead I decided to have a cooperflag decal put on the roof. Unfortunately this did not go well - the recommended installer had never before dealt with such a decal, and the result was unsatisfactory. In addition the colors of the decal were very washed out in comparison with the deep Indi Blue of the car.
So I decided to spend big bucks ($1500!) and have a Union Jack painted on the roof by Sublime Restorations (the company used by MINI Peabody for bodywork. We used true MINI colors (Indi Blue and Chili Red over the white roof) and the result is stunning!

Aero kit front plate bracket
The standard front license plate bracket partially covers the lower half of the grille so I chose to have the bracket from the aero kit installed instead. I had the bracket painted at the same time as the rest of the trim, and it looks much better with the grilled not covered.

Chrome Grille (from MINI Cooper)
At the time you could not buy a chrome MCS three piece grille (you can now), so I had the four piece chrome MC grille fitted instead; chrome works very well with Indi Blue!

Driving (Rally) lights
The official MINI rally lights look great on a MINI; much more subtle and cute than any aftermarket lights - but very expensive ($700 fitted!)

John Cooper signature decals on hood stripes
I bought some low cost John Cooper signature decals from eBay and stuck them on top of the factory bonnet stripes. Two years on, they are still stuck!

Greenstuff brake pads
The Green Stuff brake pads are one of my most regretted purchases and are strongly NOT recommended! The claim is that they reduce brake dust (maybe) so that you don't have to wash the wheels so often - lie! White wheels get dirty due to road dust as well as brake dust - the Green Stuff pads make a negligible difference.
On the other hand, they do squeak terribly if you don't have the optional "anti-squeal kit" fitted (bits of rubber behind the pads); and they have made an awful mess of the rotors, which are now deeply scored. If I replace the pads I will go back to stock - because the Green Stuffs don't brake as well in everyday driving either! But I will have to replace the rotors as well.