I inadvertently misread my dipstick and put about 3/4 quart too much oil in my 1.8L. It has an auxiliary oil cooler. I ran the engine this way for about 600 miles until I could change the oil. Did I do any damage? Thanks for your insight.

nope

Auto crossers do it all the time to avoid oil starvation under cornering.

I always ran extra quart, most of it will be out in the heads once you get running anyway. And the best part is the crank is not sitting down in the oil zone of the Type-4 so its not whipping the crap out of the oil. Cam and lifters could be, but you would have to severly overfill the engine to even submerge them in oil. As it would start going out the push rod tubs, and filling the heads also. And we all know pushrod tubes will leak anyway.

That being said your fine, matter of fact I would keep that your new normal, as a 914 can have oiling issues on the street also. Long sweepers are the worst.

Type IV have a self leveling oil system. They drip down to the correct level.

Don't do it in a six

You still won't hurt it but the engine will look like Mom and Dad left teenagers home alone for the weekend! Oil everywhere!!!

An Extra quart used to the norm for track work or hard driving leave it

Did that on my first AX with the /6. It was fine on the street but once i pushed it around the cones it started puking out the vent holes in the catch can.

At least my engine won't rust with all the oil on it ...