[texanidiot25]

1. If you have 2 grills, Block the upper first. This will generally cause you to induct slightly hotter air in the summer as it is closer to the road. However it will keep the blocked air rising over the vehicle undisturbed. For the same reason, if you have a single grill, block from the top, not the bottom.

How is the upper grille closer to the ground?

I can't say how accurate any of this is, being that I'm a total n00b, but my MINI has a functional hood scoop, which tells me I can probably block both the upper and lower grilles without messing with the car's cooling too much. I have makeshift grille blocks in place right now, and I took the car for a spirited drive today to see if the temp. indicator threw me any red flags, but I saw no problems. Any thoughts on whether or not to expect problems later?

I can't speak for the supercharged Mini, but the Turbo used the hood scoop for the intercooler, if I recall right. I'd be leary about blocking it.