[infinitiblast]

Good lord your jumping all around with ideas. First of all why would the heat only affect Nissan's? Who does this tow truck driver work for the dealership?

Secondly get the car towed home like everyone else says. Pay you 150 dollar diagnostic fee and don't ever let that happen again.

Once home pull the coil packs and plugs, visually inspect and smell each plug...are any of them wet with gas. I'm not talking about carbon, I mean wet. If so shine a light into that piston to see if there is liquid...if so you will need to get that out with a suction device depending on how much it is.

Unbolt the front fuel rail, lift it up high enough to see the tips of the injectors. Do you see any gas leaking? If not have someone turn the key to the ON position (DO NOT CRANK THE CAR!) and see if the rising fuel pressure pushes any gas out. If not reinstall the fuel rail bolts. The intake manifold will need to come off for the rear injector's.

Its possible that an o-ring moved, or finally let loose letting loads of gas into the cyl. Depending on your speed you might be ok on the rod being bent. It would be similar to hydro locking but with gas..

I tried to start my VG with 250k miles and had it running at one point when an injector nearly lifted out of the seat, and poured gas in. It sounded like hell when it stopped...but runs fine now that its fixed.

Stop getting excited about the probability that you motor is shot and you could do a swap etc.