will the 2013 street bob battery cover fit on a 2006 or are there any companies that make one in that style how its flat and black?

 

I can verify that a 2013 Street Bob battery cover will fit an '09 Super Glide, which uses the same battery cover as your '06 Street Bob.

So yes.

https://www.hdforums.com/forum/dyna-...-06-dynas.html

 

All '06 & up Dyna battery covers are interchangeable, so yes.