There isn’t a car park at the Black-E unfortunately. There is street parking in the road beside the building but only for 2 hours max. There are car parks nearby – in order of closeness there’s one on Knight Street (£7 all day) but it only has space for 10 vehicles, then there are bigger ones on Duke Street and Parr Street which are £5-6 all day (and one on Colquitt St which is £1.50 per hour). All within 3-5 mins walk
Check out the map here (which doesn’t show the Duke St one for some reason)
Hope that helps!