Does anyone know if it is possible to remove and replace the clear plastic lens that fits over the instrument cluster, and if so, where I could buy one?

I took my 2006 3.6 to a full service car wash earlier this week, only to find that they somehow cracked the lens. Whether they pay for it (voluntarily, at least) remains an open question, but I suspect that it would be a lot more likely if the whole cluster didn't have to be replaced.

Thats some pretty tough plastic to break. I have not heard of anyone replacing this. Instrument cluster yes, this no. My suggestion would be to try a boneyard. Sholdn't be too hard to find.

It should be servicable, call your local dealer and ask them if it's available.
I have ordered them for trucks, not for CTS yet though.

Similar things happened to me, except the detailer didn't crack it but scratched it right down the middle. To top it off, he proceeded to park the car without the emergency break and it rolled into the middle of the parking lot. Fortunately no cars were driving through when the caddy rolled.

GM only sells the entire cluster as an assembled unit, if you can believe it. In Canada, it costs almost $600.

I guess this is way things work nowadays: manufacturers contract out for finished sub-assemblies, one of the consequences of which is that they don't have to carry as many individual parts.

Someone has to make the cluster, though, and if anyone knows who that is, perhaps I could buy just the lens from them...