So it's yet to arrive though I've bought two of these 🙈. They are kids toy amphibious cars with wheels that fold up when you enter the water. There's two small thrusters that provide thrust.
So plan is to keep one for my son and the other open up and replace the toy grade components with hobby grade. Overall from a few YouTube videos I can see there's ample room for a standard servo for the wheel up and down movement and after ripping out the main board there will be space for a esc and a receiver. Was thinking instead of differential thrust to fit a small rudder and have both motors pushing at same time. There's a watertight battery compartment that will fit a 2s lipo nicely.
Will post some photos up of the conversion. Should be quite interesting 🤔
Overall I have set a budget of £50. I've already got a transmitter and receiver. Car cost £12