I am new to painting autos. I was planning on painting a frame and undercarriage, engine compartment satin black urethane. I was planning black SPI epoxy primer. My rationale was that if I ever developed a superficial paint chip or scratch, that the epoxy primer under the paint is the same color and it would be less obvious. My buddy who has restored some cars says he prefers grey primer under black paints so he can see coverage. I get his point, but unless you have poor eyesight, wouldn't you see the coverage since the paint is wet when put down? TIA.