Not so sure the analogy is for Big Oil/Big Auto is quite the same but there are parallels I guess.
I don't see Big Oil doing much to help GM, et al, by helping with field prices or offering to assist with shipping micro cars (in US terms) from Korea to create a market to replace the SUVs and Trucks that currently seem to have suffered a sales death.
No reason they should try to help of course. Reduced consumer demand means less investment required and higher current stock-in-hand valuation so in the short term. If GM hit a wall it will have little effect on Big Oil.
Likewise with the lettuce growers - though slightly alternative views on this.
Tomatoes will still be available but there may be a short term dip until the 'muscle' toms from Mexico can be replaced by other sources. Toms, or a substitute will be around in enough sufficiency and with enough confidence in the salad concept that lettuce sales will likely not suffer - so long as no one accuses Big Lettuce of making people ill. Big Lettuce will be happy to see someone else taking the aggravation I would guess.