Standard operating procedure on VHF/UHF voice repeaters is when you announce your call sign, it's basically an implied CQ.
After the repeater IDs, and you hear someone else announcing their call sign, they're announcing they're available also.
Next time this happens, say their call sign, then your call sign, and say something like, "Hi, name here is ... Currently driving south on highway XX."
And that should start up a conversation.
Side note: I hear several nubes on the repeaters these days who are lost, confused, don't know what's happening, not listening to what the other side is saying, and asking questions or saying things that are confusing to anyone who is listening. I hear hams with experience doing this also. So if this happens to you, just say, "thanks, didn't catch you name, 73, <your call sign> listening." And then put your mic down for a while. And if they keep saying anything that doesn't make sense, leave your mic down.