I don't think you'll find a "Non-Dealership" that will perform 'smart' upgrades at NO CHARGE, if at all.
If you're simply looking for someone to do routine maintenance, that's one thing. BUT for warranty work and any 'FREE' upgrades, you're going to have to deal with a smart center.
Check out Englewood and Edison as they're really your best bet for service as well, unless you're planning on doing the maintenance yourself.