Much like all E53's of this age, the soft touch rubber doesn't stand up well to bejewelled fingers. The drivers door and passenger door were pretty tatty in look, despite my car being a low mileage example.
The rear doors aren't as bad, but you can still see a few marks on the lower half...

Found some cheap leather look embossed black vinyl on eBay, bought around 1.5m of the stuff for something like £6.
I sent out the wife, who's certainly more arts and crafts orientated than I, with some tracing paper to come up with some sort of template, transferred it to card, so I then had a nice solid template to start drawing round and cutting the vinyl. Getting the template right was not easy, it took several attempts to get something I was happy with, and even an attempt or two test fitting some vinyl before I was completely happy with the shape.
In the end, came up with a template from the drivers side, and happily you can turn it over for the mirror image passenger side.

The vinyl suppliers suggested the use of soapy water on the surface first, before applying the vinyl, that way you can move it around until you are happy before you start applying pressure and some heat. Too much soap and they were flying around all over the place, too little and they were starting to stick quicker than I'd like, so a bit of trial and error, but plenty of vinyl left over should I get it wrong.
Simply used a hairdryer for the heat as I gently massaged out any wrinkles, and I'm delighted with the result...

Unfortunately, the door handles in the back are slightly longer, so I'll work on a different template for them but I'm in no rush, the fronts were the priority.
In an ideal world, the vinyl could be more matt in colour, but its surprising how well it matches in with the leather grain on the door cards. Time will tell how long it will last before it gets tatty, but it's been installed for a few weeks now and looks just as good as the day it was fitted. I have plenty of left over vinyl, and it's a quick job now to replace it in the future, providing I hold on to the template.