I don't know how old you are
@T6ChrisO , but think about what job you'll be happy at in 10 years time. Will you still want to be cleaning cars?
People underestimate how much work it is.
I was running my detailing business (with staff) for four years as a student. Cheapest detail €400 and always fully booked.
It's nice to thing about standing in the heated workshop and see the latest coating on the GT3RS - but holding the machine for 20 hours and having to push into the night because it needs to be done isn't as glamorous as instagram.
I can't imagine being on someones drive in the winter with wet hands for £20 - and then get told there is a fly on the intercooler "thought that is included for the price..."
Go into detailing and talk to local clubs, visit a Porsche, Ferrari, what ever meeting. The owners have a few more cars and more friends.
Also the "rich" are much easier and nicer. Never had stress with a Lambo or GT3 owner - but you don't want the Golf boys..
How much do you want to take home every year? How many cars a day? Material is not cheap.
It's not realistic to work under £60/h if you pay tax and want a few weeks holiday a year.
Some days will have no work at all. Don't talk to dealers, they want the all-in package for £15/car.
Send me a text if you need more information.
If I would do it again I would offer dent removal and spot repair.