Sounds like an ambitions project! I don’t have any good ol’ ambys, rickshaws, lorries yet, but I have a bunch of assets that might help https://devilsworkshop.itch.io/3d-low-poly-car-game-asset-pack-vehicles-free
Hit my my main side for assets - and if you want something specific, leave a message and I will send you free downloadable keys to grab any paid asset packs https://devilsworkshop.itch.io/