I use carboard behind the grill on my wife's vehicle (diesel - not a LC), install it in the fall, take it out in the spring. It doesn't fully block the radiator, but blocks quite a bit of it.
But I like the plastic core flute idea, I think that's a great use for a political yard sign (no matter who you vote for).
But I like the plastic core flute idea, I think that's a great use for a political yard sign (no matter who you vote for).