turbo buicks without udercoating?

[mybuick]

what color if any would be under the car if there was no undercoating?

 

[aminga]

Frame will a blackish gray waxy stuff. Body will be a poorly sprayed version of the body color.

 

[regan j]

Frames were coated with cosmolene to prevent rust. I dont think there was a color to it but after a few miles color develops from roads and such.