I have done most of what SpewerCT suggests.
CA DMV has no opinion on the matter. They told me legally I can do whatever I want. If I break it, hey, it's mine to break.
CA Highway Patrol said they also don't care what I do as long as MINIMUM standards are met. The trailer has good tires, the trailer has good lights, the trailer has its own brakes if over 1000 pounds, safety chains are used as back-up to the ball hitch. They also said they don't care about what the tow vehicle is as long as it is poweful enough to keep up with the flow of traffic. They also basically said it's my vehicle to harm if I choose. THEY DON'T CARE.
Since I own three trailers, years ago I called about obtaining trailer insurance. SUCH A THING DOES NOT EXIST. The trailer is always covered with the same liability coverage as the towing vehicle. (Basically car + trailer = 1 vehicle)
I owned a smalish hybrid at the time. The owners manual said "Towing is not recommended". A lot of times this is a blanket statement. They worry you will be disappointed with performance when towing with an underpowered vehicle. At no place did it say "towing is illegal or dangerous with this car". (It does not say that in the Bolt manual either.) Hitches for the hybrid were commercially available from MULTIPLE WELL KNOWN VENDORS. I told my insurance company of my intentions and there were NO EXTRA PREMIUMS, FORMS, or anything special required.
In an accident, you can/will only be blamed for root cause. When trailering, it would need to be PROVEN that the size / weight of the trailer was the cause. Fat chance since the Bolt EV is quite powerful, has more braking ability than most cars, and is HEAVY for it's size due to all the batteries.
Pulling a trailer is not inherently scary, difficult, or dangerous. Particually in CA and a few other states, any vehicle combination with more than two axles is legally limited to 55 mph or less. Going a bit slower when towing is the #1 thing to consider along with allowing proportionally more stopping distance.
BUT FROM AN ENGINEERING AND SCIENTIFIC VIEWPOINT - towing a trailer of total weight 1000 pounds puts practically the same acceleration and braking demands on the car as putting five 200 pound people inside the car. So yes Virginia, if you pull a trailer, you should put less weight inside the car. Wind resistance makes it more difficult to accelerate but easier to brake, so lets call that net zero on wear & tear. Lets not nit pick about the resistance of the (probably two) extra tires.
A for the manual- there are dozens of errors and omissions, and I'm guessing multiple VERSIONS out there, and no doubt there will soon be REVISIONS.
I called a lawyer since SpewerCT said he isn't one so I can pass on some legal advice. The owner's manual is a GUIDELINE to be used for BASIC information and not legally binding.
As for talking to your dealer about towing. I'm still laughing out loud at that one. They SELL cars. They sometimes bolt stuff onto cars, replace tires, and do fluid changes. But they are only experts at SELLING cars. Asing your dealer about towing with the bolt is like asking the guy at Best Buy how a TV works. And I don't mean how to turn it on, or if you should turn it on. I mean how it works.
Step #1 - Talk to trailer and hitch companies about pulling with your Bolt. Explain the horsepower, torque, and gross vehicle weight. (The real experts)
Step #2 - Buy a professionally made hitch from a nationally recognized brand. Have it professionally installed. They might avoid a mistake you may make if you have never done this. Should not cost more than a $100. I've had it done for free if I bought the hitch from the same people - since normally it only takes 30 minutes or less and needs only a few tools.
Step #3. Start small, light, and slow. Tow a trailer EMPTY of contents first. See how the car behaves. Get comfortable with the empty trailer behind you.
Step #4 Add weight. Drive slower than normal. Do not exceed 55 mph. PRACTICE in ideal weather and daylight.
Step #5 Drive conservatively. Plan routes (and parking) that does not require backing up. A counter-intuitive aspect is, the SHORTER the trailer, the more difficult it is to keep going straight in reverse. My 22 foot trailer is a dream to back up compared to my 8 foot one. Semi drivers have it made with their 53 footers.
Step #6 have fun as your confidence grows if this is for recreation.
I'd be happy to chat with anyone with specific questions in PM. I really am a towing expert and own or have owned a wide variety of trailers and tow vehicles over the years. Zero accidents or incidents in 25 years and over 100,000 miles with a trailer behind me. I have towed a few hundred pounds up to 15 tons.
-John