Question for you: There's plenty of British actors & actresses who can pull off very good American accents, but in your opinion are there any American actors/actresses who you think have pulled off a decent British accent? Johnny Depp seemed to have a passable one in "From Hell" and everyone says Gillian Anderson does a spot on Thatcher in "The Crown."
If you think this is bad, you should check out Brion James dreadful cockney accent in Tango and Cash.
As for US actors who can do English convincingly, the first time I saw Spinal Tap I was convinced Michael McKean, Christopher Guest and Harry Shearer were English. At the time they were not known in the UK. Had me fooled.
Yep, Van Dyke's terrible accent is well known. I was surprised at Cheadle's casting because I figured Hollywood had learned from the Van Dyke casting blunder. Apparently not.
I'd completely forgotten about the Spinal Tap crew! Yes, excellent British accents. Guest's father was British so that gave him a bit of an advantage, but McKean and Shearer are both very American.