Tow Bar for 4 down

Roadmaster Falcon2 tow bar with their EZ5 baseplate. Used them on my Chevy Sonic and they were great. The tow arms can hook directly to the base plate connectors ( which can be removed when not towing). Using same tow bar with my Jeep.

I am a fan of Blue Ox. Have used their tow bars for over 12 years now. Not sure what the weight of your Chevy Sonic is but just make sure you get a tow bar that rated appropriately. Also, don't forget to get a supplemental braking system for your Sonic. Several easy to use systems are available from Brake Buddy, Roadmaster, Blue Ox, etc.

I would say a motor home mounted tow bar. Your car is pretty light so mounting a tow bar on MH will decrease the load on the front suspension of the toad. I prefer Roadmaster equipment, but any of the major builders will work. You can do a search oninternet to find very good used ones.
Think about your lights. I have used different types over the years. Magnetic, auxilary lights and hardwired. Over time I have found hardwired properly installed is best for us.
If you decide to install an auxilary braking system, get one that can stay in place. SMI Stay-N-Play or the Roadmaster Invisibrake. You would just need to turn on a switch. No components to move in and out of driver's area.

Roadmaster Nighthawk. Full review:
https://learntorv.com/roadmaster-nighthawk/

Whatever system you get. For your use, get one that stays attached to the motor home. Roadmaster and Blue Ox are 2 of the best ones out there. You won’t need anything more than a 5k lb rated bar.