I expect this has been done to death but as a 'fairly new owner' can anyone give us some good tips for getting rid of the mess this stuff makes and can you press it back up without causing any problems? Perhaps you just cut it off!

Thank you very much! That's very helpful Randa. Happy Christmas!

Actually, if you pick off a chunk of it and roll it up into a little ball, you can sometimes use it like an eraser to "rub out" the residue. That tends to be a bit less risky than the scraper. Then, as Pete says, clean up with white spirit.

Cameron at Automotive Leisure told us that excess black mastic along the joints was something to be valued — it meant that they'd erred on the generous side when sealing the panels in the factory.