So, you are looking for an alternative. Bus? Could be, but it takes ages and often goes only 1 or 2

I guess it happened to you as well, that you were planning a trip and checked hotels close to port of miami the offers from the german train and thought what the f*** . Yes, often it is incredible expensive to travel with the train. Especially if you prefer the fast ICE trains.
So, you are looking for an alternative. Bus? Could be, but it takes ages and often goes only 1 or 2 times a day. Flight? Yep, makes sense, especially if you go from one big city to another. But to find good deals can be hard sometimes as well.
It started maybe 10-15 years ago, that people who were driving with their cars from one to another city, offered to take other passengers with them and to share just the fuel. So they save some money and even have company. I think this in one of the best solutions: it is really cheap, it is faster then the bus, it is comfortable and you have company as well (if you don t like to talk all the time, make sure to let the driver know that you are really tired ahead .
And yes, it is all in german, but actually really easy to understand if you don t speak it. Just choose the cities from which to which you like to travel, the date and you ll get a list of all the offers. Then you only need a phone (or a friendly receptionist in your hostel hotels close to port of miami who helps you) and call the person with the offer done!