We get the concept behind the plastic BMW Fan Blade used on almost all BMWs since the dawn of time. It's lighter in weight and it can be shaped to precise airfoil angles. But still, if any little bit of debris hits the BMW fan blade while it's in motion, it shatters into a thousand pieces. We've also seen older BMW fans that cracked along the hub: the plastic became brittle, and one cold start was all it took to destroy the BMW fan blade.

If you've got an older BMW with a bad fan, you may want to consider upgrading to an electric fan setup. The engine-driven fans on old Bimmers were marginal at best, as you probably discovered at many a red light during the summer months. An aftermarket electric fan can help keep your car cool in the most demanding situations. If you want to stick with the original-style BMW fan blade, just be careful: That plastic gets more delicate as time goes on.