If that was a demo, then I'd pass it.
Lease return.
I'll get him to take another look at the RDX tomorrow, because it's likely to be more reliable than the X3. From what I remember though (shopping for my mom) we didn't like the forward-angled headrests (why do so many vehicles have these now?). Also felt a bit twitchy on the highway. But it wasn't atrocious, so it's worth a second look before dropping forty grand.
Regarding the A6 Avant... my dad really prefers the high driving position of vans and SUVs. We did look into an XC70, which probably has a similar ride height to Audi's Allroad, but it was a no-go.