I just had the rear spoiler removed from my 3 week old 180TTC. I felt it ruined the rear lines and don't plan on driving 120mph on the autobahn any time soon.
I took it to my local body shop who has done a lot of work for me on other cars. It came off with the 4 bolts and had a double backed tape type stuff on it instead of the epoxy I had read about on the forum. He then welded the 4 holes up, sanded it and painted it. You honestly can't tell where the holes were and it looks stock and the way the designers intended it to.
It took 3 days and $492 and I have the original spoiler unharmed save for one small scratch for a future owner to reinstall if they so desired (although I don't know why anyone would). It was worth it for me.