I would go back and have whoever worked on it and have them put the heat shield back on!! I have taken other cars to the shop and find all kinds of little things missing.

Recently, I have been just going back to the dealer for work on the car. I have been lucky in that they have done a good job without stealing parts off the car!!

If the factory's engineers put the shield on the car... You need it!

Enjoy your Fine car!! Bill