Hello

Is it ok to mount a bicycle rack on the rear windshield ?  

I picked up a used bicycle rack in my local area.  It mounts nicely direct on the glass with two (2) straps attached to rear hatch, top and two (2) straps attached to rear hatch, bottom.

The bike carrier is weighted onto the rear windshield for support, and I'm concerned that road vibrations may cause the glass to crack.

Is a rear windshield mounted bike rack ok for vanagons ?

Thanks,
Shawn.