Oddly, in both the past and at present, both GM and BJ have been very forthcoming that many of these collectible vehicles are not road-legal, selling them with disclaimers that they have salvage or display titles and that they cannot be registered. That apparently isn't sufficient for NHTSA, which likely fears that some successful bidders will attempt to plate vehicles which may or may not have all of the required safety equipment to be roadworthy.
According to Sports Car Market (via Inside Line), both parties are actively pursuing a resolution, but according to Il's report, it may not happen fast enough – about 100 GM Heritage Collection cars (click here for a list) are scheduled to go under the hammer beginning today and running through this weekend.
UPDATE: We've just received this statement from Barrett-Jackson's PR agency – "The Acting Administrator of NHTSA, Ron Medford, has communicated to Barrett-Jackson that previous issues concerning the sales of the GM Collection have been resolved and all sales can go forward."
[Source: Inside Line]