the idea i got from the armadillos was to get starting capital then expand to other vehicles. not thoroughly tested other strategies. game is working again for me after i found the correct fix that didn't cost me anything. there was too much confusion for me for a while about this game. the patch will work if you run it from the game folder. game will launch from gog but that won't patch it. this was confusing for me. but i got an itch to try again and it worked. might play this game once in a while still.

I didn't try to continue with this guide because of the bugs in the game. game breaking bugs. i might try play it again and save more often because this game does not autosave. i don't know if the vista patch can work with the steam version or even if i can get the other version of the game without another purchase.

and look for the presents on the map (only visible on not Paused)

better if the map and orders allow buy and use tankers, they cost less but give same sales.
then if the tank industry is used to capacity, use his guide.
orders with stars get up to 3x better sales and mass orders are also good (instruct as much vehicle as you need to that orders)

Is this in general or for a specific level?

short but good