From the “redirect the vents” side of things, I’ve been doing this manually for the 7 years with no ill effects. Last year I added a Flair system and Ecobee to automatically balance using the registers. They have back pressure detection to prevent damage to the HVAC system so there’s always enough vents open. At least in my scenario it’s been a game changer for the third floor of our townhouse. As we’ve headed into warmer months our bedroom is actually cool in the evenings and the lower floors are normal temperatures. During the winter our living space on the second floor was cozy without blasting the bedrooms and making it too hot to sleep. With the number of vents I had it cost just over 1K to do, but that was way cheaper than it would have been to have the house and system rezoned.

I’m into smarthome stuff so now I’ve actually got room level presence detection going and tying that back to Flair with Home Assistant so we only cool or heat occupied rooms. Wife is a very happy camper in her now temperature controlled office, and it only targets the office when she’s in it.

When I bought my 3 it was $2200 including the harness for my car. Now the newer 3X is $1450 including harness (economies of scale!). I’ve been running it for 2 and a half years now and have 80,000 miles logged in my unit.

I’m using it in a 2016 Civic Touring which was their original dev car model so it’s well documented and had a modification available to get necessary torque in tighter highway turns and be able to slow to and resume from stop. Other cars may work better or worse in terms of torque and ability to control speed. They have pretty extensive vehicle listings on their site and GitHub detailing the capabilities they are available depending on the car.

https://comma.ai/shop/comma-3x

I don’t work for Comma or anything, just am a fan of the tech and how it has allowed the controls in my car to get better over time rather than being stuck with what they shipped in 2016. My wife’s 2021 CR-V has better stock driver assist than my 2016 Civic, but my Comma’s assist experience today is far better than either stock system.

A Comma 3 driver assist system for my car. I drive a lot for work, and it’s an absolute game changer for driving distance as an enhancement to the stock LKAS and ACC systems. Highway miles are dramatically less strain and effort, and it makes me more able to watch the flow of traffic and keep an eye out for hazards. Their tagline is that they’re “making driving chill” and it’s definitely the case as long as you have a fully compatible vehicle.