I think that would be shit. Nascar lost a lot of fans when Toyota got involved, and they would again lose more if Honda were to join. Not gonna lie but Honda doesn't really have a place in Nascar, less so than Toyota. Honda has made one RWD production car (S2000) and has never made a V8 engine outside of Formula 1. Sure in Nascar all the regulations are so strict that it really doesn't matter who makes it and the only difference are what body stickers are on the car, but Nascar is out of Honda's league. Toyota at least has made tons of RWD production cars. Toyota has a very aggressive stake in the US markets. Toyota seems to always push that they are best, and they really made a statement when they joined an American racing sport, dominated by only American companies, and the fan base consists mainly of hardcore American car company enthusiasts. Honda doesn't really follow the same advertising and have been content with their share of the US market.