Roof rack advice Solstice GT on a BMW X1

I current have a Current Design Soltice GT which I transport on my MB GLK350 with factory equipped Thule car top racking. I am in the process of repacing the vehicle and am considering a new model, the GLA. It appears to be very similar to a BMW X1. The Thule spec. for an X1 calls for a max. distance between cross bars of 24 inches. I currently have mine set at 48 inches on the GLK and am concerned that 24 inches will not be sufficient for the almost 18 foot long GT.

Anyone out there have any experience to share?

I would not assume
that the racks or limitations on the BMW are the same as the mercedes. Find out what the new benz calls for and go from there.

FWIW I cartopped a 17’9" kayak for years on a rack with