Is it practical to have a car while in the coast guard?

Yes, I don't think you have to worry too much here. I can say that in Maine the USCG gets much respect and if you really needed wheels, a community member would step up and make sure you had wheels regardless of your credit rating and all that. 

They know you are there for SAR for everyone from yachties to commercial fishers, and not doing something they might have an issue with like fisheries enforcement. In small coastal communities everyone has a loved one or buddy who works or plays on the water, even if they themselves stay ashore. You might end up with a rusty old Sube this way, but at least you won't have to hitchhike.  I don't know about the rest of the US on this. 

Members of the Coast Guard spend more time on land than on water. They don't live on ships.

Not having a vehicle would be impractical in most cases.

Practically a necessity since most CG bases do not have housing available.

You do need to get to your job every day and not all Coast Guard stations have barracks so you can be required to live out in town. You can also be stationed in one place but also have to go to others a few times a month.  If you don’t have one now, don’t buy it wait until you are stationed and know you will need one. Make sure you get something cheap but reliable. 

It depends on where your stationed.   Like if you were at one of the Coast Guard Stations in Oregon a car would be a good idea, even if you were on a ship.

Its pretty much of a must have. lots of coast guard stations do not have barracks, so everyone must live in an apartment in town-- so you gotta have a way to get to work everyday.

Yes, their deployments are not a long as the navy

Unless you can afford Uber on a daily basis.

Hello Mark.

It won't matter because you won't make it through basic training.

Yes, where are you going to be stationed?