I've only done the Indy 500 a bunch but that's it (I really have no interest in racing beyond that one weekend) but yeah, you can defs feel the rumbling and vibrations. I'm HoH so I don't bring my hearing aids and I wear earplugs. I don't know what it's like during a Nascar race, since they don't use Indycars
Do you live in Indy? NASCAR has a race there
http://www.ticketcity.com/nascar-tickets/brickyard-400-tickets.html