Davidka - Most prototype testing is done at the club-race level (and most of it doesn't get run at club races). The pro drivers out there are not running stuff you can't buy, because winning with sorry-it's-not-for-sale equipment is bad press, and honestly, it's unfair to accuse the factory teams of running one-off stuff. Usually, the only time this happens is when it's close enough to production that they can talk about it if someone sees it. Associated and Losi do this, Thunder Tiger, Kyosho, Mugen, OFNA, most of the factory teams follow these guidelines more or less. Not because of any sort of unspoken gentlemen's agreement or anything, but simply because of marketing.
Adam Drake is sponsored by JBL, Kortz was working on a deal with Rockford Fosgate but that might've fallen through. There are many Monster Energy Drink sponsored drivers (I think Richard Saxton might be one of them), and I know NOS Energy Drink is looking to get in on the action. Saxton and Jared Tebo are sponsored by Smith Optics as well.
Terrorists may not care that there's a concentrated group of foreigners, with a large number of westerners, racing toy cars for bowling trophies and a world title, but being part of a concentrated group of "the enemy" is kinda scary...not to mention that not only will we all be at the track together, but many of us at the same hotels, flying on the same flights into the same airport, etc.