It's rare to see a restored car fully undercoated. I usually do it on mine since I drive them. Although I do agree, it can look like your hiding something, but if done right, I don't think it does.

68 Road Runner, 69 Belvedere, 71 Challenger Vert
340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z
66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram