Well, it's 8:40 pm and I got home about 20 minutes ago.  The last 8 hours or so have been quite an adventure.

We drove back from Barra de Navidad today, after an excellent few days with our friends on Oso Blanco.  About 40 miles from PV all sorts of lights went on the car.  From what was happening (power steering not working, AC suddenly warm), it was pretty easy to see that the car had thrown a belt.  We were in the middle of nowhere, so I decided that even through the alternator was no longer powering anything, there ought to be enough energy in the battery to keep the electric radiator fan running and keep spark going until we could limp to the next town.  Stupid.  Belts power water pumps, too.
 
It didn't happen.  The car died about 3km short of Tuito (about 30 miles from Puerto Vallarta).  There just happened to be a bare spot on the other side of the road, and as I opened the hood to look at the steaming remains of my engine, a guy pulls up on a very small motorcycle.  He looks at the situation, introduces himself in broken English and says, "I'll get a taxi.  Be right back".  He turns around and heads back to Tuito. Ten minutes later he leads a taxi back to where we are.
 
Liz and I get in the taxi and head to Tuito, where the taxi driver has a favorite mechanic.  Mechanic in tow, and we all parade back to our car.
 
The mechanic opens the hood.  His English is excellent, "Your water pump is gone".  
 
So, we are back in the taxi to go to a car parts store in Tuito.  Of course, no water pump.  After heading back to where the car is to tell the mechanic what is going on (and to get the old water pump), me, Liz and the taxi guy head for the Jeep dealer in Puerto Vallarta, a 45 minute drive over curvy roads.  When we get there, we find they are closed for another 30 minutes, so the taxi driver takes Liz home and comes back for me.
 
Water pump and new belt in hand, we head back to Tuito to pick up the mechanic and head to the car.  I paid off the taxi driver in Tuito and jumped in with the mechanic and headed back to the car.  It took him all of 10 minutes to mount the new water pump and belt.  Just before he asked me to try the engine, he checked the oil.  Oops, wayyyy too much.  Bad sign.
 
Sure enough, the engine wouldn't start.  Heads probably blown, or worse.
 
We discussed the situation, and determined that my now-favorite shade tree mechanic Alex could probably do a reasonable job of figuring out exactly what had happened to the car.  The problem was that we needed a tow.  Alex had an idea.
 
We drove back to Tuito, he jumps out of the car, and walks over to a police truck.  Then Alex comes back and tells me to come over and get in the police truck with him, and the three of us drive off at a high rate of speed toward my poor car.  The lights were a nice touch.
 
Alex produces a very worn piece of rope, and attaches it to my car, then to the bumper of the police truck, and off we go back to Tuito.  Even the policeman was skeptical about Alex's tow rope.
 
The rope broke going over a tope (speed bump) near Alex's garage, so he coasted there with me giving a little extra push.  The tow cost me a 200 peso contribution to the police benevolent fund. 
 
So, that's where we are now - I'll know by 5pm tomorrow if Alex can fix it.  
 
We are philosophical about it.  We couldn't believe our luck to have someone who spoke English stop right after we broke down.  We were also very lucky to be broke down so near Tuito, the last town with mechanics before you get to PV.  We got a very, very patient taxi driver who probably drove us 60 miles total.  The car is what it is - it'll either be fixed or it won't be.  We'll have to see what happens after tomorrow.