I've heard of people getting nailed for having too much rubber fuel line in the engine compartment. I'm doing the fuel lines on my VW all stainless hardlines to make sure, but I'm wondering.. does this rule also apply to oil cooler lines?

nice avatar. answer is no it doesn't. i have worked tech for a few years, and the major concern is fuel. but, be sure your oil lines are not gonna get torn or cut and that they don't leak if you are using rubber.

General rules 2:14

"All transmission lines must be metallic or high pressure-type hose."

This means the rubber hose you use to attach an aftermarket cooler must be transmission rubber hose. It will say transmission right on the hose. Rubber fuel line used as tranny hose will not pass a tech inspection. There is no limitation as to how much rubber hose you use like the fuel line specifications.

All lines going past the bellhousing should be either metallic, steel braided or are run inside a metallic protective tube in case the flywheel/flexplate decides to explode.

Thanks for the info.

Just to keep things on track, the question was referring to engine oil cooler lines. Now do stainless steel braided lines fall under the rubber hose or the hardline category?

Steel braided is not "rubber hose". The goal is to have the hose protected so that it doesn't wear against anything or that it can't be easily punctured.

Thanks. That's exactly what I needed to know.