Found this from ‘barnstomer’ in a previous thread:
I spent ages looking into this, largely because the VW cross bars sit too low to the roof for an inverted kayak to not rub the roof. The clamp system also isn't the strongest as the bars sit between the rails rather than on top which is desirable for load clearance.
I've historically used Thule bars on other vehicles but they don't actually have any certified for use with original VW T5/6 roof rails (same part). I had a conversation with their technical department having emailed a cross section profile of the roof rails but they still weren't very helpful and indeed didn't seem to know their product or the potential market with Transporter owners.
However, both Thule 757 and 775 feet kits will fit and will accept any of their bar systems. you'll need 150cm ones, the other options are all too short. The 150cm bar will oversail the rails slightly and could be cut down but will need some filing on the underside to accept the end caps securely.
I went for second hand 757 feet (older and often available cheap with chuck away bars on Gumtree!) and 150cm wing bars
Buy Thule 757 Railing Rapid System Foot Pack For Cars With Roof Rails Roof Bars at Tredz Bikes. £74.69 with free UK delivery
Buy Thule 963 Wing Bar 150 cm Roof Bars at Tredz Bikes. £76.49 with free UK delivery
775 feet are a more recent design, and use a tensioned rubber coated thin metal strap under the body of the foot. A recipe for metal fatigue I reckon if they are going to be on and off regularly rather than a 'fit & forget' solution:-
Buy Thule 775 Crossroad Railing Rapid System Foot Pack For Cars With Roof Rails at Tredz Bikes. £95.69 with free UK delivery
Both feet kits come with locks.
Unfortunately despite some retailers suggesting otherwise 150cm wing bars are only available in silver finish in the UK. I wanted black to match the rails and could have bought them in the US when I was there but for over US$200 a pair.
Tredz seem to be cheapest in UK, wait for the £5 discount pop up code to appear before ordering and order feet and bars separately to save £10!
Cheaper aftermarket T5/T6 vaguely aerofoil bar kits are available on Flea Bay, but I made that error before with cheap bars on my Golf and discovered the top channel wasn't wide enough to accept Thule bar accessory mounting bolts that slide in the channel. Burnt my fingers on the grinding wheel paring them down (bolts not fingers).
If you are fitting your own VW roof bars make sure you use sealant, not a factory fit spec though. The receiving nuts in the roof are in oversized holes and the foam rubber gaskets that are supplied with the bars are as useful as 6 chocolate fireguards at stopping rainwater in the gutter seeping into the inside of the roof. Plenty of gen on this issue elsewhere!
