Exhaust seal location

I never heard of an "exhaust wrap".

You should be hearing the results of an exhaust leak, and that should make it easy to locate. The seal you are likely referring to is commonly called a "donut" gasket. It sits between the rear exhaust manifold, and the exhaust pipe. Those parts are held together with two spring-loaded bolts. Those allow the joint to move and flex as the engine rocks. If that joint could not flex, the pipe would break within a few miles.

Those donut gaskets cause very little trouble. In the early 1990's, the biggest problem they caused was a tiny annoying squeak when accelerating away from a stop. When they leak, it is almost always caused by a rusted or broken bolt.

Some engines use thick metal gaskets between the engine and the exhaust manifold. If those, or the donut gasket leaks, you will hear a noticeable ticking sound when accelerating. That can let exhaust fumes enter the van through the heater's fresh air duct in front of the windshield.

If the only symptom is fumes getting inside the van, but the exhaust system is quiet, a better suspect is the tail pipe got bent when it hit something while backing up. Other potential causes include a rear side window is open or the rubber weather seal around the lift gate is torn or missing.

It is important to know the difference between gas fumes and exhaust fumes. If it is raw gas you smell, but there are no obvious leaks, a good suspect is a leaking o-ring around a fuel injector. Most of the time the leak is fast enough that you can see some wetness around that injector while the engine is running. If the leak is too slow, the gas will evaporate before you will see the wetness, but the leak will continue after the engine is stopped. That is when the wetness may stay around long enough to be spotted.

You need to be a bit more specific. There are two actual exhaust gaskets in the system. Exhaust manifold to cylinder head, Exhaust manifold to converter. Then there is the EGR gasket. Plus there is the flex pipe. Those are the common leaks. Unless the pipes are rusted. The pictures are the manifold and front pipe gaskets.
If the bolts are rusted either of them can be a tough replacement.

I do not have any idea what was done. When I worked at a very nice family-owned Chrysler dealership, I was allowed to bring customers into the shop to show them what was found, and explain what was needed to solve the problem. Not all shop owners allow that, but in most states you have the right to have old parts returned or made available for your inspection. If you have anything you can post a photo of, I can tell you what it does.