Dash done tomorrow install carpet.
Since the lower windshield trim piece is already on there, you can also use one of the Dr. Clock tricks: @Alan Merklin
Run a piece of blue painter's tape along the trim piece approx. 1/8" up the trim. Make it even all along the trim piece.
Run another length of blue painter's tape along the cowl about 1/8" forward of the trim piece. Make it even all along the length. Use your fingernail or a popsicle stick to make sure the two closest sides of tape are really adhered along the length.
Shoot a bead of silicon caulk between the two pieces of tape, right along the trim piece. Don't worry if it overlaps onto the tape - that's what it's there for.
Once the bead is done and before it sets up, evenly remove the tape from both sides, leaving a smooth edge on the cowl and trim piece.
Dr. Clock may chime in with more tips, but that's what I remember him telling me to do if the trim was already attached.
Use " Alex" brand from ACE Hardware the latex caulk .. has a small % of silicone in it. ( Don't use silicone caulk) The " Alex: caulk is flat black and closely matches the rubber . The spacing on the masking takes is less than 1/8" you want just enough caulk to seal the area between the aluminum and cowl.
If that gets wet does it crumble