Maybe focus on driving while driving so as not to kill yourself or others.
Who doesn‘t think about stuff when driving alone, unless you‘re still learning to drive? Do you also not talk a word to anyone in your car because you have to 100% focus on driving at all times? No offense..
To actually adress the OP question:
It depends on what you‘re trying to learn or „practice“ I guess.
I‘m learning TULPiH ZBLL, and so far I‘ve learned 2gll and one additional H set. I often just go through those sets in my mind, and imagine the algs for each case. That helps me especially with similar looking cases, for example the T and U 2GLLs that look like a T or R perm from a certain angle. I kind of imagine doing the algs. It‘s not muscle memory of course cause I‘m not doing them, but it‘s also not thinking about the algs as they‘re written. It‘s something in between, like imagining how the alg feels when executing. For reference, just think about a T perm. For me I kind of almost visualise my hands doing the alg. What‘s also helpful is imagining AUF before the alg of any case, so I learn how that‘s supposed to „feel“ and wether or not I might benefit from doing U with a left index push for example. After all, if I recognise a case from another angle, the auf should be automatic and part of the alg.
At home when I learned a set of algs, I often go through the set, as in, I think of a case and what alg it should be, and then do the alg on a solved cube until I end up with a solved cube again. For me that‘s the most efficient and beneficial way of getting the set to stick. I only use a trainer to dill them after I‘ve done this.
So when driving I essentially do the same but in my mind.