I don't have numbers to prove it, but I believe Toyota does outspend GM and Ford, per car supported, and it worries me quite a bit. Toyota has expanded the role of the manufacturer by taking on several crucial functions that have traditionally been race team responsibilities... more of the nitty gritty design and engineering, young driver development programs, engine builder, subsidizing the truck team, and maybe more. These things shift costs from the teams to the manufacturer, and to the extent the teams pay Toyota for it, they are not paying full fare IMO. Jack Roush's early concerns have been proven valid at least partially.
This worries me because Nascar and the teams are becoming more and more dependent on the deep pockets of the manufacturers. In response to Toyota, Ford recently has increased their commitment and their expenditures, but for how long? And Chevrolet may be lagging behind, we don't really know. But if the Toyota business model costs more than the traditional Nascar model, that makes it easier for the factories to justify pulling out.
One thing I've learned from five decades of studying many forms of motor racing is this... the manufacturers *always* leave, sooner or later. We can't blame that on Toyota, but altering the business model to shift costs to the factories does hasten the day of reckoning, I believe.
The party is in full swing now, but when it ends the hangover will be severe and long lasting. If Ford leaves, that will make it easier for Chevy to leave, and vice versa. If history repeats, Toyota will leave Nascar like the Colts left Baltimore. That's just the way companies work, including Toyota and all the others.
And meanwhile, Nascar continues to rake in huge profits, ISC and SMI continue to rake in high profits as well, while the manufacturers and the race teams are getting squeezed tighter and tighter. That part ain't pretty.