It`s as fragile as a new born babe. Hit the kerbs once too often, you`ll be waving goodbye to your suspension, or tyres, or both. Stomp on the brakes and they`ll break. Over stress the engine and it`ll blow up.
The most important part about NSU - avoid gravel!:-D I never had issues with damage, even in close racing, but I got stuck in gravel traps way too many times.
NSU for me are great and fun cars to drive, quite difficult indeed. No TC no ABS and the mass transfer affect a lot, aswell as the way you change gears... so if you wan to go "fast"... you need to drive very good. fights can be close without loosing the car when someone touch you, so there is more and better action