I've seen the under coating being applied at eastern Motors and I would advise you against it. It is extremely important that there is no air or moisture pocket when the undercoat is applied otherwise it would lead to even greater problems few years down the line.
Plus there is this notorious issue in a lot of new fortuners that water accumulates in the left rear door. On the day of delivery ask the service guy to generously pour water on the left rear quarter glass area and then after 2mins open the door and remove the rubber drain plugs underneath. If you see water draining from there then your car has that issue too and dont accept the delivery.