This is not economically motivated - I have comfortable free cash flow and a healthy balance sheet free of personal debt. I pay for a car service and take taxis more than public transportation and pay more than the average U.S. homeowner's mortgage payment in rent. I also spend a great deal more than my parents, who find my behaviour and preferences baffling, on travel and technology.
I won't disagree that a significant fraction of decreasing home and car ownership may be explained by economic factors, but would caution that (a) there is a significant minority that is making these choices as a matter of preference, and, (b) for the rest, these behavioural changes, initially motivated by economic conditions, could become ingrained to where they persist beyond economic weakness. With the second point I'm not saying we will be a "cheap" generation, just cheap traditionally, as we spend in categories we value more than piles of sticks and little steel boxes propelled along asphalt by exploding chemicals.