I think I’ve just been whoooshed.
Could you put a life size erect golden metal or plastic penis on your car's hood as a hood ornament?
Yipes! Pardon. See, just one more reason to hate those things.
A man with an ornament like that must think himself inphallible!
Would you like it explained? Or is it over your head?
Thats a hint right there son 
Come on, you can work it out!
And his taste inpeckerable.
you can put one on, but the angle of the dangle must be less than 45 degrees.
The answer is simple. Pay $50.00 online to become a pastor in the Universal Life Church. It is totally legit, you can legally marry people, do funerals and best of all it is tax exempt. They encourage you to start your own church so all you’ve got to do is start the Universal Life Church of the Golden Phallic.
This will allow you to proudly display a big golden stiffy for a hood ornament. You will also be able to wear a fat golden weenie on a gold chain around your neck so the chicks will know what you’re all about.
Make it out of soft rubber, so it just flops around randomly in the slipstream.
If it’s based on Michelangelo’s David, then it has redeeming social significance.
It would probably depend upon the local jurisdiction. I have a friend in old 'bama, and they don’t take to kindly to trunk nuts in his town. Well. they like trunk nuts. They just don’t like it when those truck nuts place those testicle sack replica on their truck hitch. Porn prosecution is local and it all has to do with community standards and some communities don’t stand for very much.