The Genesis version of Virtua Racing here has the credits/game end music in its set.
I was surprised to find no signs of a 32X ending version in the checking I had done at the time.
However, in the 32X anniversary album, there are 2 tracks for Virtua Racing that aren't in the pack. And understandably so, as they're apparently very difficult to find during normal game play.http://www.youtube.com/watch?v=T3ifPiYLo4s
Here's a video of the ending
So, in order to get that, you'd have to play every course on hard and finish first in each, apparently. This is a nearly herculean task; I can barely finish first on normal difficulty most times.
Furthermore, the US and Japanese versions of the game apparently have different music during that section, if the album is any indication.
I've never gone under the hood and tried to hack the music in the game, though, so I have no idea if there's an easy way to trigger those two tunes to play in, for example, the sound test.