I used a local independent electrician in Simi Valley, CA to install a 14-50 NEMA outlet in my garage with a 40' conduit to the breaker box. Although he may not have experience installing a Tesla HPWC, I'm sure he would be capable of doing so. PM me if you want his contact info.
i just had a local electrician install my 6-50 nema outlet. had to upgrade my panel for the backordered tesla power station. but when i get it he's going to switch it out and put the power station on. his rates were either equal and better than solar city. i went with them since they are local so cal family run business and they were in no hurry to install. solar city may have all the experience, but they are booked & always rushed. i wanted someone to install it right. not rush and throw it in to get the job done so they can get to the next install. plus gehpart electrical worked around my times not their times.