I agree with the 'filling the outline with black' suggestion.

 

looks good as is

How much does that material cost?
and how hard would it be to take off?

 

The stripping tape is about $3 a roll.
I bought 2 rolls just to be safe.
The stuff I got was from auto zone, and it had a ragged cut on the removable liner that caused little pieces from the liner to get under the tape during application...so shop around for some better tape.

It has survived a few trips through Mikes car wash, but will easily peel of if I want to remove it.

It's fun stuff to play around with.
I laid out some guide lines using a china marker (grease pencil) which made it a lot easier to keep the lines going where I wanted.

Get some and play around, It's cheap therapy