Not a grille but I want 60’s and 70’s style American lights and badges (Especally that red / red and blue lights).
I wouldn’t request any specific grilles, instead I’d like to write a little suggestion.
Would it be possible to have the bumpers as separate fixtures on pre-'80s cars? In the current state of the game the bodies came with a standard, fixed bumper design which you cannot modify freely.
The shape of the bumper could make a big difference on the appereance of a car - at least in the age of chrome bumpers. In the mid-80s bumpers became integrated to the general shape of the car, due to aerodynamic reasons, but befor then they defined the “face” of the car in many cases.
So, is there any chance to have move-able and interchangeable bumpers in the future?

it would be cool if we could have “body kits” that support alternative bumpers and sideskirts!
Another point, comparing bumpers from European designs and North American ones. Many European cars that can be bought here are different from ones that sold in Europe due to safety regulations. A number of 1980s sports cars come to mind.
And you mean…
e38 body
What car grills do you want added to the fixture library?
Well, that escalated quickly.
OR headlights