1994 Ford Escort Rear Impact (Is this car tough or is it the full size spare?)?

1994 Ford Escort LX/ Sport 4 door hatchback. 6 months ago I was stopped at a red light and was rear ended by a 2010 Chevy Suburban that was traveling at 55 mph. Got out of the car and found that there was a lot less damage on the car than I was expecting. There was no intrusion into the passenger area, and only 4 to 6 inches in the cargo area. I was still able to drive it legally afterwards. The rear quarter panels were intact completely, it just messed up the bumper, rear panel and slightly buckled the cargo floor. The car did have a full size spare instead of the donut spare, and it was inflated. I don't know if that had anything to do with it or not. I know they say built ford tough, but does this always happen with the escorts or was it a lucky break? Let me know.

Also, The rear end was not re-enforced. I gutted the interior to get to the bumper bolts and found no bars or anything like that.