Greetings. Ah a TDI, I would love to have one of those, twice the torque and twice the gas milage
As for grill blocks, I would be surprised if there isn't somebody here with a TDI that has tried it already. If not just block as much as you dare and go for a spin, if the temp needle moves, make the hole bigger. Thats how I'll end up doing if if I make a grill block for my car.