I did a FULL detail (7+ steps). As such, it was probably quicker to tape things and not have to worry about the edging on all the different steps. Also, I was using Intensive Polish which is more agressive and harder to remove. If I were just doing Final Polish, I might skip taping.

I found taping pretty easy. I used good tape (3M blue) and kept the car out of the sun. Came off easily and a little goo gone quickly removed any residue.

This really falls into the category of "whatever you prefer."

MODS/UPGRADES:
17x8" BBS RKs (great AW story about how I got them...) | H-sport anti-sway bars | ToyGuy short shifter |
IceLink/iPod integration | Escort 8500 hardwire | fog/running light rewire | HomeLink home lighting control |
fold-down bag hooks in the trunk | aux power socket under the armrest | hidden Symphony EQ settings |
remote locking control recode | debadged

SUGGESTED READING FOR C5 A6 OWNERS:
2001 A6 info from AudiWorld | 2001 A6 info from Edmunds.com |
Audi 2001 maintenance schedule | Stoney's links (the ultimate A6 links page) |
the nOOb's guide to everything | how to make your car shine

The other ride: 1998 Mitsubishi Montero (typically with a kayak on top)