topherD wrote:Besides avoiding it, is there any way to protect my engine from fast shifting?
What do you mean by fast shifting? Protecting the car against high RPMs from revving, or protecting against changing between gears in a short span of time?
If it's the former, first and foremost... Avoid it! Nothing can protect your engine against conditions it wasn't designed to do on a regular basis. The next best protection is synthetic oil, but it is by no means a substitute for careful driving.
If you mean changing gears quickly... Nothing. Your engine is not going to take the abuse. Your flywheel, your clutch, and your transmission will. You cannot use synthetic transmission fluid in a Versa, and NOTHING but proper driving will protect your clutch and flywheel.