ADB disconnects frequently while moving in a car
Since you are sure that its not a port/USB wire issue and since ADB does detect phone, its not a driver issue either. Hence saying what the real problem is likely not really possible to be accurately predicted. ADB is a very "delicate" stuff. A slight connection problem causes disconnects... My best bet here would be loose connections. You should certainly try with other computers if you can.

For timebeing, there is one thing you can try if you debug while phone is on (and not in recovery or fastboot mode), ADB through wireless. Like using your wifi for adb. The adb client will be on your laptop and you can issue commands just like normal to phone through your laptop. Although modern ROMs have inbuilt option for this called ADB over wireless which you can find under settings-&gt;developer options. But in case you dont have that option, you can also use third party apps that allow you to do so like ADB Konnect.

Just install and open any such app and it should give you an address according to wifi/network you are connected to. Lets say it gives you 123.456.7.8.

Then open CMD/Terminal in laptop and use the command adb connect 123.456.7.8 to get connected to adb. Then you can issue all your commands as normal.

The downside is that your phone Has to be on. So in recovery/fastboot etc, you cant work using this.