As a truck driver and someone who had a wife that enjoyed showing off, I have knowledge of this subject. Twenty years ago, "hooter shots" and ladies enjoying themselves while driving were not uncommon. Now everyone is looking at their phone, including most truck drivers. If your wife would like to show off, here's my advice. Pass the truck, let her look to see if the driver pays any attention and is a suitable candidate. Get a few car lengths in front of the truck and then begin to slow, this should get their attention. When you get back even with their window, she can do her thing. Although not as common as in the past, some trucks still have CB's. If so, anyone that's listening ahead of them will be on the lookout. Bonus tip, if you come up on an old school type truck like a Peterbuilt or Kenworth with a running light hanging off of the mirror, thats what it's for, looking in cars at night.