In my book it should within the gentlemen's agreement that one has to solve a puzzle alone and without help from others.*
Think it's quite different if you found an unknown car and ask for help somewhere to post it later here as a future puzzle.
* I would never ask somebody else...even not my father. He's got no clue
I can think of some scenarios where the concept of
alone might be "violated" yet in total innocence and without any intent of cheating. Consider this as an example: A friend comes to visit and sees the puzzle car on my computer monitor. He says, "I know that car...it's a 1924 Rolls-Canardly." Or he might say, "Yanno, I saw that car on a website last nite. I think we could find it again because I was searching for a 1982 Carpmobile (credit/apologies to Otto) and if we look here at this site...." The friend might also say, "I saw that car in one of my books. I'll call you when I get home and tell you what I find."
Another situation might be to ask a friend if he remembers a certain car at a certain location/event (race/LSR cars could easily fall into this situation)...like "Do you remember a car that ran at Bonneville around 1970 with turbine power?" Is this any different from googling "Bonneville turbine" or something like that?
Taking the idea to the point of reductio ad absurdum, one might say that using one's own collection of printed or digital material would cross the "alone" boundary and THAT would completely prevent me from playing/competing, since, as I've written before, I have post-perfusion syndrome: in other words, memory damage from a bungled coronary bypass surgery. This and the fear of Alzheimer's Disease is one reason that I find AP so enjoyable, since it keeps my mind running at more than idle speed (or comatose, if I were to spend my days watching the idiot box.) I hope that a constant "workout regimen" will keep some of the brain cells alive and functioning.
Anyway, aside from "Google Search by image", I don't see other methods of solving puzzles as a bad thing.
Just my nickel's (tuppence, franc, pfennig or whatever) worth
RtR