It's funny that that's exactly what I'm wondering about mobile phone chips and much less so about automotive. After all, whatever chip is inside an iPad 3, is still very usable to me and other than games, I don't see anything really that's going to require a lot more processing power.And which of those things requires 4x1.8+GHz Cortex-A15s and Tegra 4's GPU? Still not following this at all. All of it should be possible with a relatively modest CPU with competent media acceleration.
I have a limited amount of experience in the field of automotive: the qualification cycles are absolutely brutal. Think chip process stability and aging, high and low temperature robustness, operation in a very noisy environment, and, let's not forget, rock solid software stability over hundreds of thousands of cycles. And an army of anal-retentive German or Japanese engineers who will ding you for every little deviation from whatever spec they want to adhere to. And paper work: mountains of them.
It takes a couple of years before an producer is willing to make the jump to include it in their platform and only then do they start to actually design it in. With Tegra being only ~3 years old, the big ramp up in volume, if there is one(!), should be ahead of us. It's just too early to declare it a success or failure there.
As for price: I would not be the least bit surprised if this outdated $20 Android cell phone chip sells for $100 in the car market. In fact, that's probably low-balling it.
So with that said, bringing up Tegra 4 in this context is way too early. You can't see an automotive application now that requires a quad A15 and amped up GPU. But do you believe that automotive engineers won't be able to come up with something for deployment 5 years from now? Because if Tegra 4 ever makes it into automotive, that's when it's going to be in its prime.