Except Universal is the company that has built massive, impressive, practical New York streets sets in the past. Twice, in fact. Kongfrontation and MIB. Plus Spidey, in a slightly less grand way.
Yes, space was incredibly limited on Fallon's plot, but if we pretend that there was a giant plot to work with, I could easily envision a racing-type attraction through street sets in a huge show building. I mean, that's still what I wish we were getting with Fast and Furious.