Footprint is 2×5 m. Sheet volume is 2×5×0.002 = 0.02 m³. Titanium density is 4507 kg/m³. That gives 90 kg. Without the aluminium deflector.

Normal Tesla Model S curb weight is 2108 kg according to Wikipedia. Extra 90 kg is 4.2% mass increase => 4.2% more kinetic energy at the same speed => more energy consumption to accelerate. It also means, that the same force applied to the heavier Model S will accelerate it slower (a = F/m).