Fit - size wise, the Motion XT XL fits the GLC perfectly, couldn't have gone much bigger, I think the XXL would have been too big. Quality - The Wingbars are a nice bit of kit, but I am slightly disappointed with the roofbox itself, the quality of the plastics on the bottom half being quite poor and very flimsy. Only time will tell if it stands up to the rigours of use. Weight - I didn't check the weight of the roofbox before I purchased it, let me tell you its heavy, 4.5KG heavier than the Mercedes one, that might not sound a lot but when you are trying to lift it onto the roof by yourself you feel all 23.5KG of it Looks - Good Price - Expensive
What's the maximum weigh you've loaded onto the roof. The manual says 75kg. BMW X3 is 100kg, C-Class Estate ranges from 75-100kg, model dependent makes a difference somehow... (don't see it myself).
I have a similar setup to Visa, but with a slightly smaller box. Thule Wingbars and the Thule Motion XT L.
I'm looking to try fit the box with two bikes. Thule 561's where the front wheel comes off and locks onto spokes. The weight is going to be close to 75, borderline exceeding. Would definitely be less than 100kg.
Roof Rails and fittings, 5kg
Bike carrier x 2, 3kg
Combined bikes, 25kg.
So about 53kg without anything in roofbox. Looking to just put clothes in softbags in the roofbox, plus a few long items, beach brollies etc. Think the softbags will be about 5kg and get about 7 in. So another 35kg taking the weight up to about 90kg, 15kg over what Mercedes recommend.
I'm trying to see if I can lighter things up in the box than clothes to bring weight down). Wary it's over and not sure whether to risk it, otherwise I'll annoyingly have to loose a bike.
I've always bought Thule but I found the genuine Merc GLC bars are better. The tool-free adjustment and rubber padding on the feet are far superior to the Thule.
Only downside is that the Merc bars have to be fitted at specific points on the rails as the width cannot be adjusted. So, if you carry long loads, the Thule might make more sense as they can be placed much further apart.