It all depends on how your car is running at the moment. If you're not experiencing over-heating issues then there's no reason to use waterless coolant. If your car is overheating, then waterless coolant will show up any shortcomings in your system. Unlike conventional coolant, the waterless variety is often environmentally friendly, which means it can be disposed of down a drain - but be aware it does cost a lot more than traditional brands. Originally developed from NASCAR, it was popular with race teams because they ran their engines at extremely high temperatures. As for ceramic coating your exhaust manifold and having a professional carbon clean done, both have their benefits - but do you use your car enough to warrant spending the extra cash? After all, you're unlikely to see a return on your investment should you sell it.