I figure I might as well start somewhere.
Today I timed myself with a deck of cards for the first time (third attempt overall), and successfully memorised it in 9:49.76. I'm quite astonished I made it under 10 minutes, and it's really encouraging, although I didn't time recall.
My main issue wasn't creating the images or remembering what card came next in recall, it was just trying to remember what card goes to what image in memorising. I had a lot of trouble memorising the 4 of clubs, simply because I couldn't remember the image of a car.
Hopefully I'll improve tomorrow!