Underside Finishing

[Plum6Pak]

Finally got the frame rails in, the underside all cleaned and primered to the rear leafs, any thoughts on how you would finish it? I really don't want to paint it the same as the body color but I don't want to just undercoat everything either. I thought about undercoating the floor pans and all the sheet metal areas and paint the frame the same as the body. What's everyone else doing on theirs when they aren't painted the the same as the body?
Any pictures would be very welcome!! The more the better.

Here's where mine is at right now. Once I get this part done, in goes the engine and trans.

[Hemi Challenger]

 I don't have any pictures But why can't you mix Paint into your Undercoat and paint everything the same color and it would last your life time just my 
 it does look nice like that  nice and clean but you got to keep out the rust somehow

[Plum6Pak]

I don't have any pictures But why can't you mix Paint into your Undercoat and paint everything the same color and it would last your life time just my 
 it does look nice like that  nice and clean but you got to keep out the rust somehow

That sounds like a good idea, if undercoating is paintable, maybe I could just undercoat everything then spray it with the plum afterwards. I don't have anything that will spray undercoating, I was just going to buy the good 3M rubberized kind and spray it that way.