[LEAKYSEALS951]

THIS!!!!! (is the beauty of product photography...) You have a fixed focal length (If you have a tripod).

Back to the future:
"Where we are going, we don't need autofocus"

The bolts aren't going anywhere.

And with a tripod, neither is the camera.

You do not need autofocus at all. Switch to manual.

Luke- "you have turned off your targeting computers...."

On the picture of Matt (the guy I took a MTB pic of) - I think I disabled autofocus on the shot. The MTB riders were coming down a 2 ft wide singletrack. I was standing stationary. I didn't need autofocus, they were in a (fairly) set range. I set DOF as wide as possible to include them in the pic (within reasons for low/natural light- it was raining in pic/overcast) and instead of worrying about distance from (me- to - them) I worried about left to right tracking.... In your case, You know the distance and the subject is not moving. I'd focus on the half-axle splines (perhaps the brake calipers) as focal points as a starting point (because they seem to be the midpoint between raised/ and on the table focal lengths, get a reasonable DOF and go from there.

edit- another (constructive suggestion)- When you are lining up the bolts / etc. in the pics, use a ruler on the bottom edge of the bolts to line up their position. Then remove the ruler and line up the next line of parts in the next column down. This will keep the bolts lined up in perfect up/down alignment. To help with multiple rows of bolts, I would use a yard stick, which is very long and would overshoot the picture right to left. Out of picture shot (to the right and left), would be a board with graph / measurements/ markers to keep the yard stick in alignment from one row to the next, but out of sight of the pic. This would make product layout quick and easy.

p.s-- I'm liking the 1/4 window release handle pics! At least in terms of contrast/tonal value. They do look (again constructive) like, perhaps a mismatched pair, but that could be the angle, especially if you are shooting at a wide angle. I would also angle the allen bolt on the right window release knob down to be not visible.(as a side note- any 911 I've owned without that feature- I've installed it with the corresponding windows! great upgrade!)
Good luck!