vapor locking in fuel injected motors is far more common than you think, anyone who says that f/i engines don't vapor lock is completely WRONG.
first off, fuel injection systems due to safety issues have a much reduced pressure than they used to have, if you look at the pressures in older fi cars it was around 60 - 90 psi, it is now common to have 40 - 45 psi in the system when it is running.
the above and the non use of summer or winter blends in hot regions, substituting them for a sort of average blend will boil in the fuel line given sufficient ambient temperature, with half a tank of gas and an outside temp of 110 degrees i have experienced vapor lock, i measured the temp of the bottom of the gas tank, it was 159 degrees and a hissing oozing noise could be heard from inside the gas tank even with the filler cap removed so the noise was not any form of pressure relief valve in the tank or purge system, it was not the fuel pump running either as it had completed the prime cycle with the key on engine off.
the above was exasperated by driving the vehicle at a constant highway speed for 100 miles give or take 20 miles, thus having a small amount of fuel passing through the injectors and most fuel being retuned to the tank.
if the vehicle was left for ten minutes, then it would fire up but die almost immediatly, however with the hood open it would fire up and continue to run.
the ignition system was in as new condition and the engine temp was below 200 degrees and the ac was off.
the above was a "return" system.
another example was a non return single line system which are becomming more and more common, on this system by depressing the test port on the fuel rail vapors would vent and if you continued until raw fuel came out, then the vehicle would start, clearly "vapor lock", i have had this occure on Ford, Chevrolet and Chrysler vehicles so no common parts here, the only common things were the fuel and the ambient temp.
some manufacturers are aware of the problem, and have devised a solution in the form of a fuel cooler connected to the ac, Jaguar and Mercedes come to mind, chrysler have increased their fuel pressure to help eliminate the fault as have other manufacturers, unfortunately, people with older cars who live in the south west are out of luck unless they can find a way of cooling the fuel or raising the pressure but with the modular design of fuel pump/regulators it will not be easy.
an additional regulator and gauge could be fitted in the return line of a return system and even in a returnless system like the later rangers, it could be added in the return line between the filter and tank but this would need an aftermarket regulator and gauge, but systems with a return built into the fuel module it is not easy at all.
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