We have to stick with Thule's recommendation for your 2018 Volkswagen Golf SportWagen and stay with 47 inch long crossbars with the roof rack part numbers # TH711200 and # TH710401. Going with shorter crossbars hasn't been tested so it's very likely they wouldn't be long enough. view full answer...
The correct replacement fork skewer for the Thule roof-mount Tandem Bike Rack # TH558P is their part # 8535256. The # TH535SKR is not recommended for the Tandem, according to my contact at Thule. ThruRide Fork Adapter # TH535SKR is not a fit for the Tandem. view full answer...
Having the 4-way run out of the back hatch is actually the preferred method although it seems like it wouldn't be. Having the 4-way stored inside the cab of the keeps it protected from rain and moisture to prevent corrosion and keeps it protected from damage to the wiring or connector by rocks or debris that might be on the highway.
You can run the wire through the vehicle if you wish but just keep in mind that this does take more time and you may end up needing additional wire because... view full answer...
The majority of Thule Cargo Boxes you can add locks to by obtaining lock cores, the Thule One-Key System part # TH450200. However, this is not the case for every Thule Cargo Box so I would really need to know exactly what model you have in order to recommend the correct locks for it. If you look on the inside of the box for a sticker that would then have the model number that I can use to make sure you get the correct locks. view full answer...