The spine was one of those things that didn't scale up well. By the time you double the weight of the car, it just isn't rigid enough. Europas worked pretty dang good, but it didn't translate into v-8 land. Just like you can't make a cockroach that is six feet long. It couldn't stand up or breath cause it would not be able to support the weight via exoskeloton. Some things just don't scale well.
BTW, Ema is still looking good for being close to 70.