I believe it's reasonable that if a company is too large relative to the market, then restrictions on dealership ownership & control make sense to prevent collusion and killing seller competition.
However, for a smaller car company, such rules work against it, protecting the big boys from competition, which was allegedly the reason for the dealer restrictions to begin with.
Thus, cross-sector collusion rules should be tuned to mostly apply to companies with a large market share of car manufacturing. Maybe a way can be made to make the restrictions incrementally higher per market share percentage rather than have blunt cut-off points, which is one of the criticisms of ObamaCare in relation to employee count and work-hours.