Use what works. I have a similar set up as you described and have given thought to purchasing one of the fancy stands/holders I've seen at the LHS...but never really found a solid reason as to why I need to.
Clothes pins and a latex glove are very useful.
A cheese box (Velveeta) works as a good holder while painting...
Craft sticks and alligator wire clamps
Reversed masking tape and paper card stock
Homemade hold from clothes pin a dowel and a wooden base.
Dowel or tube up the tail pipe...works for decaling too
Also look to those promotional gift items that businesses give away
Find what works with minimal cost...something that you won't mind discarding after it has become caked with layer upon layer of paint and is not longer functional.