I also found out VAC has a
bolt-on oil cooler for the e46.
Was hoping to get the dimensions of our stock cooler, so that maybe we can find something we can adapt to have it in the stock location/stock size. I figure we can get more efficiency out of the package, but keep the car mostly stock. Plenty of people are tracking without issue, so it doesn't need to be a huge upgrade, maybe just a more modern/efficient cooler with slightly more capacity.