My British driving test was so long ago that I can't remember what happened; I know it wasn't perfect but I passed first time when I was 18; back in 1994, and I believe I took the test in my instructors 1.3L Vauxhall Corsa. My second driving test in the US was easy in comparison; it was literally a drive around the block and park again; and again I passed first time; I got one minor for doing 27mph in a 25mph zone.
I was thinking i wonder how our american cousins would fair in a manual on british roads!, i got 11 minors, twice as many as my first test, which i failed.
I'd probably kill a few people in a huge car pile-up. After all you Brits all drive on the wrong side while we drive on the right side (literally and figuratively).
Nah, I've driven that wrong side of the road in Jersey, but I was on my motorcycle, so the left-right issue was slightly less problematic. 
I passed first time In South Africa, also first time in England and America. Problem being, I've driven too many times in different countries, and I'm all over the place. Now that I'm back in England, I've had moments where I'm not sure if I'm on the right side of the road. It's the worst feeling in the world (well, I'm sure there's worse).
My mantra to keep me right is: Steering wheel is always closest to the middle of the road. Without it, gawd knows how many accidents I might have caused

" Fire! Fire!, Diniz in the oven" - Murray Walker on seeing Pedro Diniz's Sauber on fire