The tubing that the frame is made with is weak and has already bent making one wheel wobbly.  I only used it twice.  I believe getting it in and out of the car is why it failed.  It should be strong enough to withstand frequent collapsing and transport and it doesnt seem to be.  What I did like about it was the visibility and air flow it provided.  I needed it for a trip this summer but I had to get a different one since this one was too flimsy.  My dogs are small at 5 pounds each.