Front valence trim piece question

[royalflush313]

I have seen couple different kinds of trim pieces that goes into the slots pictured by the arrow below.
Are both slots (top & bottom) supposed to come filled stock?

I don't have a front plate right now, and the front end looks like it's missing something with the open slot on top. I was thinking of picking up the vented piece that ppl often have.

How many different kinds of trim pieces were made for those slots? Anyone have pictures?

[parkerbink]

I had the tabs on the bottom removed because I think it looks better open and I am sure getting more air on there is a good thing.

[e30evolution]

the upper one is meant to be open

[e30sd]

325i's have a vented one for the oil cooler. 318is has a blocked off one.