I got cover a couple of years on my Mercedes with Moris (i think) it was £250 for the first day, it didn't cover much and the excess was 10% of the claim, think it only cover someone else if you hit them, no barrier, recovery or your own car.
This, there is cover available but it's not worth the money as it doesn't cover the most important thing. There was a UK based company that still offered cover up until later 2017 but that has been pulled now unfortunately. If insurance worrys are a big thing, rent something or do a trackday. The potential bills can financially ruin you for life
