Both safety and emission standards are easier to retrofit on an existing large model than on a smaller one, since it doesn't require designing a tiny car from scratch to accomodate them. You just add them on to your existing and popular Belchfire . Not only that, it means you don't have to really compete with your competitors since all cars will require the same mods and all manufacturers will pass the extra costs to the consumers. This is why the patchwork of existing regulations have been pretty much accepted by the industry, while meaningful changes and restrictions have died on the vine.

I've always felt that the main reason pollution controls were pushed so hard is that Detroit felt it would be much harder for their import rivals to
engineer those devices into their cars than for them to simply add them on. It certainly killed the air-cooled VW Beetle.

But it was the Japanese who managed to not only meet but exceed those standards and still keep cars small, cheap and reliable. In short, they met the customer's needs better than Detroit, and Detroit is now
singing the blues over their shrinking market share and profits.

However, foreign marques are now falling into the same trap, building bigger and more profitable cars, that is, until the next oil crunch hits us.