What is the Titanium coating on the P99?
Is it just grey park?
The manual says it takes the same care as blueing, so it will rust––-does titanium rust?
It is titanium.
Mine hasn't rusted. It does have some spotting to it. I can't tell if it's dirt I haven't tried hard enough to get off, but I'm not worried about it. The finish doesn't seem to be compromised.
I can't say if the titanium is good on finish wear - I haven't been that rough with the gun.
Mine was almost new when I got it, and it seems to be wearing off with just casual shooting and cleaning. So far, I'm not too impressed, but it looks nice.
If you're talking about the titanium QPQ, it's quench polish quench. I remember reading on the walther forum fact that it's a silver tennifer or some such fanciness. I have one and carried it a lot and often wet from rain in a leather holster. No rust.