I am not sure I understand your question. You would do wudu the same way you normally do it. You would find a place to stop the car, take some water and do wudu. You may carry water bottles with you in the car, or you may look for a gas-station etc. In Muslim countries you can often easily find roadside mosques which would have the relevant facilities.
This answer is based on a fatwa by the Permanent Committee for Scholarly Research and Ifta as documented in their book Fatāwa al-Lajna ad-Dā'ima, Vol. 6, pp. 256
To wipe on either socks or shoes, they must have the following conditions:
Cover the feet and the ankle, including the malleolus on each side of
the ankle, which is the area that gets washed ...