So I appreciate this topic has been covered 100's of times, but that probably makes it worse rather than better , so looking for a definitive answer from people who have done it and to learn from their experiences. I drive a new E92 M3 here in Australia, front plate is required, just waiting on new one to arrive. So the question is, I have the HP heads, latest version, do I put them horizontal under the front bumper, close to the number plate or do the vertical install in the grill? As most people have stated getting the heads straight is nearly impossible due to the slant in the grill fins, even using a dremel to shave them still means they are not at 0 degrees. Also, these are illegal here in Australia, so while I understand Cliff's comments about "stealth the ride, not the install", I do need some degree of stealth. I have thought of just saying they are ultra-sonic emitters to scare kangaroos off, plenty of those things here in Australia, both roos and things designed to scare them off.
So my question for those who have done it, especially in light of needing to run a front plate, is the vertical grill option or under the front bumper number the best position?