Yes there is

there is a truck in fire red and leafgreen but you can only get them by. trading a pokemon that knows cut so you never have to board st. anne. after you learn surf talk to the guy who takes your st anne ticket but dont board the boat. instead before you get on, surf to the right and get on the platform with the truck. there is an item on this platform so bust out your itemfinder. but as far as the mew, the damn developers took out the mew so the truck is useless