[borntohoop]

would it be easier to paint my tail lights red when they are off of the car?

 

[WhiteLegend]

yeah, probably. A lot less taping required and it's just safer, you don't want to accidentally over spray onto your car. Taking out the tail lights is just 4 nuts per side, not hard at all.

 

[infinite]

Absolutely. It isn't that hard to remove the taillights, so you might as well take em off.