Danielgibbs did all the hard work to get a fit for the dimensions of the VW BT holder.. but I didn't have the old Iphone for his design, but I did have a quadlock case on my new Iphone.

And timorpatty had a great Quadlock model on his button blank adapter.

The actual quadlock adapter, wasn't accurate enough on my old ANet a8.. so after removing the support, I sanded until it did fit. You may have a printer that prefers to print, not create filament spaghetti.. so maybe you'll have better outcomes with your print.

It all seems to hold up well, even in summer temps.

I printed with the quadlock on the topside.