I also own the HTC Evo View 4G, a 7" tablet, and I use it with Sprint service. I can tell you that the app will not work on Wi-Fi. It must be connected to the Sprint network to run. I don't know if it would work on a Virgin Mobile device. Obviously they use the same towers as Sprint but what exactly the Nascar app does when it decides to run or not may allow it to know it's on a Virgin device vs a Sprint one.
If I'm feeling helpful I'll move it from tablet to phone and report. But no guarantees.
Update:
Was sitting here doing nothing tonight when I remembered this. I moved version 2.3.1 of the Sprint Nascar app from my Evo View to my phone. Runs well although I didn't check out all features. Used TiBackup to do the xfer so I could move my login and settings at the same time. Once I brought up a mobile data network the app ran fine. I'll try to remember to play with it on Sunday during the Pocono race to fully test it but I was able to view my driver and his current race stats and some of the other extras in the app to verify it was actually working.
Since its a TiBackup file with data and password protected I won't post that file. If you can't find a copy of the app ask via pm and I'll see what I can do to generate an apk I could post here but look elsewhere first as I'm not the world's most reliable sort.
Update 2:
Today was race day at Pocono. Just finished listening to commentary for lap 42. Watched some video. Listed to pit/driver radio chatter. Not sure what else the app does but everything I tried seems to work just fine.