Was over in UAE for some time. Mecedes-Benz have no probelm with the climate, the dealers are well equipped. As for gas/petrol prices, basically cheaper that water.
See the Dealer when you get there, they can do any required modifications to help handle the heat.
Mercedes-Benz Master Guild - 2 years
Shop Foreman - 20 + years - dealer.
Part owner - MBZ Transmission remanufacture