We have had the dealer replace the leaking water tank on our new Coromal 450 transforma after only 500 kms on sealed roads. Now we find that the cap on the water tank will not stay locked. A call to the dealer and was told that this is a fault of that particular brand of tank. Was told that as there is no definite locking mechanism on the underside of the cap, the cap pops out when the outside temperature rises. Anyone else have this issue? Generally VERY disappointed with the quality of this brand of van, as we have had several serious issues in the 1000kms we have now done on sealed roads. Dealership in Townsville has been very supportive.