Anthony and i talked about his. What killed it was that it was a 1998 model. Anything 1996 or later requires a federally mandated OBDII diagnostic plug-in to check for fault codes. His beetle, being a non-US model vehicle, had no such plug. Therefore, he failed the test simply because there was no plug-in. And, yeah, i don't imagine the tailpipe test would fail.
I assume the volvo is an older model, tailpipe only tester. But, i don't know for sure.
Then, doesn't matter what's under the hood, just what leaves the exhaust pipe.