These look like Wet Okole seat covers....with custom Embroidery ??
http://www.wetokole.com/VEHICROSS.html
I'm on my second set in 12 years..I love them.
They are a bit fiddly to fit snuggly..but with time and patience , they do
Wet suit material...your bum slides over them nicely for ease of entry!
Machine washable too.
I'm sure Dave will confirm...but 99% certain thats what they are .
Jo