how to tell base versus sport?

vtec to vvel

OP won't be able to tell based on SRM, as he states it's an auto.

I'm sure the OP has figured this out by now, based on the age of this thread, but just by looking at the vehicle, a few ways to tell the difference between base and sport package option for auto trannies are:

1. 19's RAYS
2. Nissan Sport Brakes
3. underbody front chin lip
4. rear spoiler

As others have states, people can simply swap out parts. And others also have stated LSD in rear differential, though I'm not sure how you would be able to check that.

With the auto tranny, though it doesn't have SRM, the models with the paddle shifters (i'm being told that the new auto's don't come with paddle shifters?) will come with downshift rev-match, whether with or without the sport package.

ideally, the best way for you to know if a particular vehicle has the sport package or not is to run the vin.