Vince, in the aftermath of an earthquake, I would be likely to use nothing heavier over me than a tent.  Your point of the garage crashing over your truck is well taken, but that wouldn't be a problem for me:  genetically speaking, no one on either side of my family has ever had a VEHICLE in a garage!  And all the junk in is is so tightly packed that even if the garage collapsed, the contents probably wouldn't even shift.
I offered the dome as I consider it:  an interesting experiment that I would like to try.  While a firehose aimed at it probably would tear it apart, the effects of gravity would tend to help in a quake.  BTW, most of the dome buildings in the middle east are built of adobe-type bricks, stacked & caulked with mud.  They are exposed to rain, wind & snow, & deteriorate at an alarming rate.  The newer method of firing these home from inside makes them much more weather-resistant.
Sue