As Dean says, this is confusing. Checking ETKA and it's even more confusing. The attached image is the driver's side switches and covers all years, so the image doesn't even show the grab handle. Based on the item you linked to, the corresponding LHD version is part number 4D1959521AB 7PE (soul/black). Searching for 4D1959521 will bring up all LHD versions, but you have have difficulty finding a black one.
BTW The part number 4D2959518 doesn't return anything in ETKA, but interestingly, I came across another eBay listing that shows a 1-part piece of trim (that Dean mentions). If you check the images, you'll notice both numbers 4D2959518 and 4D2959522 (on either side of the grab handle). The eBay listing is as follows:
https://www.ebay.com/itm/194403444626
Can you confirm if the one you linked to is what you're after, or is it more like the one I linked to?
__________________
2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts
My DIY jobs -
Replaced alarm horn,
Replaced Coolant Temp sensor,
Updated RNS-D firmware,
Installed Reversing Camera and Digital TV,
Dashcam Installation,
Retrofitted Rear Blinds,
Auto-Dimming Rear View Mirror,
Chrome Boot Struts
Sold! 
2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights
My DIY jobs -
Fan Jet Windscreen Washers,
Retrofitted Electric Side Blinds