Why not have an existing dealer in the state offer repair service?
Dealers don't confine their service department to only working on the brand they sell. I hadn't even thought of that aspect, but it seems like a good idea to work this out.
As far as the interstate commerce clause, that appears to be moot. Along with consumer rights, labor law and environmental standards in states since the WTO overruled state laws made in the seventies and eighties prohibiting goods from sweat shop, prison and child labor.
Far be it from me to say these goppers had a good idea, but this seems fair based on the premise of consumer protection. Of course, it could be what it's been alleged all along, a swipe at alternative vehicles. Here is a picture of a recent model. I'm only interested in practical transport, not luxury, so 'meh':

I don't know if this has changed, but as of 2011, it wasn't union:
Tesla employs over a 1,000 full-time employees and none are represented by labor unions.
As of December 31, 2011, Tesla has 1,417 full-time employees. "452 in manufacturing, 315 in powertrain research and development, 276 in sales, marketing and service, 216 in vehicle design and engineering, and 158 in general and administration."
Of these employees 1,088 are located in the Northern California offices, including the Tesla Factory. 81 are in Los Angeles and 48 are in the UK.
It appears the parts are made abroad and they have very few people making the cars. A good thing is that they expect to have the price of the cars down to about $20K each. A lot more details at this link:
http://www.businessinsider.com/teslas-financial-problems-and-recovery-2013-2?op=1
The technology will help get away from fossil fuels in the future, but IDK about the human or environmental impact now. We are certainly never going to return to the way manufacturing was once done in this country, apparently. This is globalization and bigger than any government. JMHO.