Well, that's not correct!If you do an RM on a car with engine tuning prior from my previous experience it will remove the engine tuning on the RM but the engine tuning will still be shown as there and you cannot buy it again, meaning you cannot get the horsepower from it back. Unless that's fixed now...haven't tried it for a while.
Well, that's not correct!
Yes, it removes the engine tuning, but you can simply reinstall it. Very easy.
YOU CAN!You can't reinstall engine tuning - not when I tried it I couldn't anyway.