When we moved to Florida I packed up my car and drove it down. Plenty of people who live here during the winter months (snowbirds) transport their cars back and forth. There are services that handle it for you but they basically charge a fee to arrange for the actual transport company to take your car.
Depending on where your dad is and where in Florida he wants to leave the car, the Auto Train is another option.
Yeah I probably should disclose that he tried to have a car shipped down from the Northeast only to get bait and switched by the guy who after taking a non-refundable deposit started to walk the price up to a point where my father didn't want to afford it anymore. So I think he would probably want something that was more of a larger commercial operation and stay away from the mom and pops. Auto train might be a good idea. He does drive his regular car back and forth it's just getting the other one up.
There are a lot of shady companies in the transport biz. Most of my neighbors make a deal with the actual driver after the first trip. They pretty much either call or text directly and skip the middle man.
As long as he's close enough to DC to make it work, the Auto Train isn't bad. I'd recommend paying the extra fee to be last on and first off. That really speeds things up.
Well that's a good idea too. Also yeah he should probably ask some of his friends who shipped their cars back and forth. I'm just doing this without him actually saying anything to me. I just think that it would be a shame to leave his car South instead of enjoying it all summer.