That was my thought exactly. Google's April Fools don't often have any link to reality (I still remember the moonplex, that was cool), so in this case because the self-driving car is already successful, it sounds stupid to have such a tiny step as a joke. Of course, the video someone else put in the comments does have some "foolsworthy" comments by drivers especially... We'll know for sure tomorrow!

Unfortunately, looks like it's definitely an April Fools Joke. (The "Interested parties" section under Future Uses seems intentionally creepy.)

The Future Uses section certainly has a joke-y tone, but if it's an April Fool's Day joke, then NASCAR has given them a huge amount of leeway.

Usage of NASCAR trademarks, hosting videos, and even linking to the video on their homepage.

I'm more inclined to believe that it's real. But I've fallen for more Google April Fool's jokes then I'd care to admit.