Standing is an essential part of prayer. But if one can't stand and pray, then they're permitted to sit and pray, and if that's not possible, then laying on the side or whatever is also allowed. The Prophet is reported to have said:
"Pray standing and if you can't, pray sitting and if you cannot do
even that, then pray Lying on your side."
It's an authentic hadith and is collected in numerous books, including (Sahih al-Bukhari)
Now the issue comes down to is whether the exemption is due to illness or being in a situation where one cant stand.
The context of the narration was in regards to illness. However, the statement of the Prophet was in general speech. So therefore, it can be taken without being it restricted to illness. And this is in regards to sitting in a car.
Now driving, well, you can pray while driving, but think of the safety concerns. Would you take the risk? Can you pull over without getting out of the car?
You cannot be excused to missing the prayer just because you're driving, unless of course it's out of forgetfulness or oversleeping.
So try to use your critical thinking inshaAllah.