I assume you have a plan of what to service soon on the new X?
Probably Engine oil and oil filter and brake fluid and pwr. steering fluid AND fuel filter as a minimum - and a tough call on the ATF (probably too early)!?

PS:
> how brave and risky to show proof to a wife that one was right!
In theory: Yes. But my wife accepted a long time ago that where technical issues are involved, she's always going to pull the shorter straw...
It even shows, when she buys the occasional technical item from a Chinese online seller herself - she accepted, that that, too, is not her strength, as she buys frequently crap, which I would never consider buying in the first place...