any advice for installing an aftermarket hood tach? Since the car is newly painted I have reservations since I dont want to screw up the paint.

Who's done it?

Use a brand new hole saw! My first attempt was with a hole saw that my contractor buddy loaned me. It went round and round until my paint bubbled. I bought a new hole saw and it went through like butter. Luckily, the bubbling paint is concealed by the hood tach.

Tape where you are going to drill as well, it will minimize chipping. Clean up (file) the raw edge and seal with paint to offset rust. When you set up your template, before you drill just look where the holes will end up underside. A slight adjustment may improve how the nuts go on and seat on the brace side.

Epoxy a small piece of hardwood on the underside of the hood where you are going to drill the hole. It will help to keep the pilot bit in the hole saw centered.

To add to the tape thing, use the blue masking tape (for paint masking) that peels easy when done.

Also the wood is the only way to insure the bit does not jump around.

I did not seem to have an issue without the wood (mind you I had a new holesaw), but it's not a bad idea....

and 4da, thanks, I was thinking of masking tape but should have clarified