great to see you're managing to put all the ideas into a sensed form!
About the sources, we could add a column where we enter all the reliable sources about that specific make.
What's a reliable source? Generally books are more reliable than websites, but you often find many mistakes on books as well, and often websites are very usefull with not so known info in them.
Regardless, it's common sense that can make the difference. Reading something on a small website isn't that reliable unless the writer provides itself some reason to at least trust him. the same goes for books. generally you can trust books as there is much more work, efforts and even a bit of authority in order to get your work printed. Still, we all recognize a well written book and even more an important book. Often many recent books are written after what you can find yourself on Wikipedia or other not so hidden websites, and even without checking the info.
So...it's up to you to trust or not something. Many people write after what companies' founders told them, but can you trust them?
In the end, among the best sources are companies websites. the problem is probably 90% of automotive companies were dead before internet was conceived. Books from the nineties tend to be good, and so prior to that. Recent books should be from good authors with some sort of good sources quoted in the books themselves (like renowned archives, workers or ex-workers from some companies, etc).
Something you'll know I suppose
When there is something about a make that we aren't sure of though, and that we can't find any sort of baking, the solution could be using something like a red colored background for its line (as we are now working in Excel), or add a "verified" or "no sources" attribute in a new column, so that only verified info could browsed during a search.
Poll