From what i've seen its very difficult to establish a high end detailing centre in Pakistan.. most people dont know about detailing and an average guy wont spend thousands on washing their car unless they're an enthusiast.
Though people have been successful but it took aloot of passion and a lot of hard work. I think that guy even spent nights in the studio, detailing cars.
Another thing ive noticed is that people are fascinated by foam washing. An average guy would pay no more than thousand rupees per car.
Thats one way to go about and then there is high end, in depth detailing. You can can charge more but you wont be pushing out more than 2-3 cars per day.. and you have to prove yourself in the market!
Best of luck... just my 2 cents.