There seems to be no public record of their contribution and no official archive or memorial.
A few years ago there were a few personal recollections recorded on family web sites, but many of these have disappeared as these web sites are no longer maintained.
The wikipedia entry implies that the women only drove in London (and/or the UK) however it would seem that there were groups of MTC drivers in North Africa and the Middle East, as well as France:
The very first official RAF escapers cannot claim much credit for their remarkable escape. ... In the Troyes district the convoy was turned back due to an expected counterattack and on returning to Villenauxe, as the convoy was directed to turn left, driver Otto turned right, followed by a second ambulance driven by Miss Marjorie Juta. The two ambulances continued at high speed through enemy territory until they reached French lines and safety back at Provins where Barrett and his crew were left at the hospital and the ambulances returned to their Headquarters. Barrett was later evacuated from France by sea from La Baule whilst Asker and Kirk rejoined their squadron. The three women belonged to the British Mechanised Transport Corps and were members of the Chateau de Blois Ambulance Corps which had five ambulances given to the French by American donors in Palm Beach. They later took their vehicles to Bordeaux then Arcachon and were evacuated from Arcachon on board the cruiser HMS Galates 21 June. (from http://www.conscript-heroes.com/Art25-EarlyEscapers.html)
It is said that after France was liberated women from this group of the MTC were given a place of honour in the parade on the Champs Elysee.
Two young women from the MTC who had been regulary driving between Egypt and Palastine were said to be the last members of the Allies to leave Cario before the German advance. Later women from this group were awarded the Africa Star although apparently this was later taken away from them by the post war Labour Government.
If anyone has any information whether from family members or from research of officials records please do add then to this blog.