Nowhere in that release does it say anything about boats, ships, vessels or any sort of water transport.
In the english language motor transport is just another way of saying motor powered wheeled vehicles.
OK, I suppiose it's a result of my misunderstanding.
Anyway 21st Panzer division had hardly got more than 2000 "motor transports".
Other german divisions could hardly have more than 1900 "motor transports" and no one knows how many operational.
Look at battle order:
The following units were deployed in a static defensive mode in the areas of the actual landings:
716th Infantry Division (Static) consisted mainly of those 'unfit for active duty' and released prisoners.
352nd Infantry Division, a well-trained unit containing combat veterans.
91st Air Landing Division (Luftlande – air transported), a regular infantry division, trained, and equipped to be transported by air.
709th Infantry Division (Static). Like the 716th, this division comprised a number of "Ost" units who were provided with German leadership to manage them.
Other divisions occupied the areas around the landing zones, including:
243rd Infantry Division (Static) (Generalleutnant Heinz Hellmich), comprising the 920th Infantry Regiment (two battalions), 921st Infantry Regiment, and 922nd Infantry Regiment. This coastal defense division protected the western coast of the Cotentin Peninsula.
711th Infantry Division (Static) (Generalleutnant Josef Reichert), comprising the 731st Infantry Regiment, and 744th Infantry Regiment. This division defended the western part of the Pays de Caux.
30th Mobile Brigade (Oberstleutnant Freiherr von und zu Aufsess), comprising three bicycle battalions.
As far as I know a static infantry division had no more than 200 trucks and cars. 352nd Infantry Division should have slightly more than 800 motor vehicles. 91st Air Landing Division hardly had more than 300 ones.
So Allies pilots claimed of at least in one and a half times more motor vehicals destroyed than Germans actually had at disposal (operational and non-operational).
I have taken amount of vehicles at the german divisions as maximum.
Look at figures in
http://www.lonesentry.com/articles/germanhorse/index.html