I worry that the auto manufacturers could be unsustainable in future and face the same fate as many midwest towns in the US have. 

Largest employers in Austin by an order of magnitude are state/local government, UT, local school districts and a couple of semi-conductor/high-tech manufacturing facilities. 

It seems like desirable land is hard to come by so I've been looking at tear-down houses or manufactured homes that can be removed. 

We not only have good professional jobs -- IT, Pharmeceutical, etc, but also a vast variety of blue collar workers in manufacturing and distribution.4. 

@Carini Rochester good points, especially the fire protection one.On the 2 to 3x greater price for tiny houses than frame construction, is that for a pre-manufactured home built offsite and brought in or a tiny home built on-site?

They hired professionals who manufacturer and install windows.

@Leonid Sapronov Most metal roof manufactures will allow you to place metal over shingles without voiding the waranty.

They don’t tell you this but It’s a way for manufacturers to dump cars off at about 14% interest without them realizing it .  

“Manufactured”?

Source: I'm an Engineer in a Fireplace manufacturing plant.