I wouldn't bother going back to the shop - fix it yourself. Gently pry the top of the trim piece so it clears the front piece along the roof, then slide the A pillar trim up to release it from the clips. Check the condition of the clips on the body and trim - replace clips as necessary, then reinstall the trim piece. It can be installed by pressing it straight down on the A pillar; no need to slide it into place. Give it a hard rap with your fist to seat the clips.
Edit: This applies if the noise is the trim rattling. If there is air actually leaking between the windshield and 'A' pillar take it back to the shop.
To reseal a windshield, our service professionals:
Carefully remove exterior trim pieces.
Locate the leak beneath the trim.
Thoroughly clean the area.
Apply a new, liquid sealant overtop the leak.
Test the fix.
Replace exterior trim pieces.
Douse your windshield in soapy water. From the inside of your vehicle, use an air compressor or air nozzle to direct air at the trim around your windshield. If you can see new bubbles forming on the outside of the windshield, you have a leak.
Air buffeting or a whistle are pretty common with Element windshield replacement. The person I bought my Element from had the windshield replaced so I would have a pristine one. Driving home (about 7 hours 55MPH) I thought the radio was putting out a weird noise. Tuning in to EOC showed me people who had been ready to sell their Elements due to this. I ended up driving back to the city of origin and took the car to windshield replacement shop. They added sealant to the top strip and Voila - no whistle. But, now I have yet another new windshield and I have wind buffeting at ~55+ MPH. I need to go back that local shop and ask for a fix. Probably when I ask them to fill a rock chip.
There are a lot of threads about the trim flying away after windshield replacement, so buffeting could be happening.
You might tape (temporarily) across the top strip and see if the buffeting stops. .