Danwolski

Drain the diff and check the fluid. I think if its blown theres gonna be bits of metal in it.

CrashTestPilot

As JUSTINTHECOASTIE said above, jack up the car, block it off properly and then get underneath and just look at things. Even if you have zero mechanical experience, there is a good chance you may be able to spot if something is broken or bent.
I haven't owned my s2000 for long and have little experience with this car, but what you described reminds me of a similar symptoms I had with my old school vw bug. In my case, not only I couldn't transfer power from engine to the wheels, I could not push the car as the rear wheels would seem to rotate part revolution and than lock. After I had the car raised up on jack stands I noticed that most of the bolts holding the half axle to the transmission were missing and the half axle was just dangling there. The S has the engine in the front and diff in the back, but similar principle applies. Some broken components are easy to spot.

If you decide to drain your diff fluid, make sure you have the right tools before you start. You will need 23 and 24 mm sockets, a torque wrench and a little $5 pump to refill the fluid. Make sure you use a good torque wrench and don't just guess the torque. The diff bowl is aluminum and the plugs are steel. It is really easy to over torque and strip the treads (don't ask me how I know ). There is limited room to get at the fill plug, so before you drain the fluid, make sure you can put a wrench or a socket on the fill plug. Open end wrench may be easier to get in place and rotate, but I had really hard time fining a wrench in that size. I ended up getting a socket and grinding it down to be very shallow. It worked really well. This way I could use torque wrench on both plugs. Also, don't mix up the plugs. The one with the magnet goes in the drain hole.

K1ngfunK

Also, check the lock nut on the rear axles (You will need to remove the wheels for this). See if it's still in the location it should be (there should be a section on the outer-most part of the nut that's been crushed in to a divot in the end of the axle) and that the axles are in good shape at this point. It's possible for these to come loose if they haven't been properly torqued (there was a service bulletin requiring them to be torqued higher than what was initially thought) or for the end of the axles to break at the lock nut (I've been with someone when this happened in their car during normal driving).

Rice069

Thanks guys for the help ended up being my rear diff

jeggy

Double check your front diff to make sure its ok and not gonna blow soon too.

JUSTINTHECOASTIE

Did neither tire turn when you attempted to hand turn?

Mondo131

You telling me you never slid the ass end out when it was wet?

Shenanigans!

z_speed

i drive like an old man.