so most of the aftermarket wheel center caps i have seen wont fit over the front hub covers, as was the case with my set of rota wheels. after searching for a set of deeper caps, and finding nothing that came close, here are a few pics of my cheap fix.
rear wheel with the center cap. silver cap with a black center
front hub with the msa cap powder coated and installed. doesnt look too bad, but the wheel cap wont fit
here is my jig for centering and drilling the front wheel caps. the wheel caps are right at 2 1/2" od at the outer edge, and get bigger towards the wheel. so, i drilled a 2 1/2" hole, about 1/2" deep in a piece of 2x6 and chiseled out the wood leaving a hole with a pilot hole. this allowed the cap to center tightly in the hole
drop the cap in the hole, and drill the cap with a 1 3/4" holesaw.
end result is a centered hole that will fit over the hub