Browsing through the seller's photobucket photos, I'm seeing:
- this ZHP
- E90 330i (two)
- Mercedes W202
- TSX
- RSX
- E46 M3Z
- Z350
... all in "sale image" style.
I'd say this guy is either a dealer posing as an owner, or rebuilds salvaged cars, or buys/flips them very frequently. That, combined with not responding to any of your guys' emails (likely because you come across as very informed and not easy prey) sounds quite shady.
// edit - searching for this guy's Photobucket username on google turns up two recent (March of this year) Craigslist ads for that E90 330i I mentioned - both posted on the same day, one flagged for removal, one deleted by him. Shady.