I've driven a number of left hand drive cars in England, changing gears can't be done as slickly (I found) until you're used to it. Bit difficult staying to the side of the road, you tend to drift into the middle.
I always change gears on the gear selector in my auto RHD 190E - if (when!) I get a 500E, it will be LHD and I'll have to learn to get slick with the selector again..
.