I have an update. The dealership located a fracture in an air line, photos below.

Trouble is, they are saying that an injector has been damaged, and the smell was from gasoline fouling the spark plugs. They quoted me a set of six for nearly $2500! The wife and I nearly fell over.

Hoping someone out there has an idea what new injectors and plugs ought to be cost us - help!

https://imgur.com/a/r517HZe