Here is a streetview from the road where the car came from. You can see the fence and yellow poles shown in the surveillance photos and if you rotate the view you can see the parking garage in the background of the surveillance photos.
The car must have been going very fast to get launched by the wall towards the US Customs facility.
It is very fortunate that more people were not killed or injured.
Yes, the concrete bases of the stop signs there in your link have a good incline which would send a speeding car up, up and away.
Your streetview is of Niagara... the eyewitness who came across as credible says he was going for a walk on Main St. when the car went flying past him.
Thanks, great link.
First time I ever got a link that allowed me to zoom and move position in the program.