I just washed my car and I like the way it looks when the roof is still damp.

Is there anything I could do to keep it this way, besides keeping a steady stream of water on it?

I also intend to seal it, but before doing so, I'd like to get it darker.

 

There are dyes for this. I've heard about a reviver called Renovo. Of course, you could recover it.

 

Can't remember if the sealers - Raggtopp/303 - also darken it a bit.

 

303 does not darken the top. To do that you will need to dye it....