Create space for air movement, around the back and top of the fridge, the base can be hole through the floor into the cabin bilge area.
The fins need air movement over them to cool the gas inside. As hot(warm) air rises this drags cool air up from the bilge, over the fins, warms the air, which then escapes out of the top.
On some 12v fridges there is provision for 12v computer type fans to be added to aid this air movement, I doubt there will be on 240v models.
If you can create the air space, then any fridge will be more efficent, with lower running costs and noise.
Even with your current set up, lowering the fridge by 50-100mm would help. (don't use the space for storage, defeats the idea!)
Bod