So I'm going to try and make this as concise as possible so apologies for the wall of text.

I have an 03r53 with 72000 mi.

Prior to a quick trip to the store I check the oil it's low, and I'm out. I add some coolant (its hot down here and sitting at minimum I want my baby cool). So to the store I go, get a quart of oil and add it.

Now when I get into my neighborhood I hear a slapping sound as I'm hitting the throttle coming from under the car, I go to neutral, no rev's no slapping sound so I pull over, and pull what's in the pictures from the bottom of my car. I'm a block away so I think I can make it. Turn baby back on and now I notice the battery light is on and staying on. Two houses down the fans kick on and the temp gauge goes up and red light comes on. Pull into the house and the coolant is boiling (2 month old coolant expansion tank) and now on my driveway.

I'm at a loss but first research suggest an accessory belt? I can't make out any numbers on what I pulled out so I don't know exactly how deep I'm in. Please spare no punches. Any input would be helpful.

 

The belt on the r53 runs EVERYTHING...
SO NO BELT...
NO ALTERNATOR...
NO AC...
NO SUPERCHARGER...
NO WATERPUMP...

So check the tensioner, the belt,and the crank pulley/harmonic damper....

 

Check and double check the crank pulley. If you can tap it with something and see small rubber pieces coming out of the back of it then it's probably toast.

My '05 did the same thing for the most part. Stuck in traffic on I-40 and suddenly all the lights come on, slightly over heating and drops into limp mode.

When I pulled the crank pulley it fell apart into the two piece. I was COVERED in rubber bits and dust.

 

Photos depict the remnants of what used to be your belt.

If you didn't run it to long, you should be OK, Yes you need a new belt...and as stated double check the belt tensioner and the crank pulley/harmonic damper.

Motor on!

 

Yes, check all things relevant and make sure they're good. We have a great Crank Pulley DIY here, which has some good detailed information. We also have a great belt tensioner DIY here and a serpentine belt DIY here, which both include great information as well.