In that case you don't need to worry about the underside of the car.....it's all panels, interior, engine bay etc. You could do that without too much headache and that's the route I'd recommend to you.

See a post in this room about cleaning (link below) - I've put a guide as to how I do things there, not comprehensive and each to their own but will give you some idea.

https://passionford.com/forum/viewtopic.php?t=180456