After a year of frequent sudden brake power assist failure, I took my 2016 Spark EV to a well known Chevrolet dealer in Kirkland for service at 30K. They diagnosed failure of the brake module and brake servo unit. $4500 later (including parts, labor and tax) it is working fine. Horrendous price but since I paid $8000 for the car 3 yrs ago and only use it for a 2 mile round trip to work over 3 yrs, with no other repair costs, I can’t really complain. These cars are now going for $12K to $16k , so I think I would break even if sold it. I have seen other bloggers report similar brake issues and hope for a recall, but I don’t think the small number of cars will justify a Recall from CHEVY or NTSB.