To be honest, if you are into really keeping your car looking good, I would spend the money on some kit and watch a few you tube videos.
Its not that difficult to get up to speed, unless of course you need some very serious work done. But even a home effort can give you 75% of what a pro detailer could get to in their premises.
These finishes took me quite a few hours work, in fact most of the day, but came out really well on both my previous Zeds
https://youtu.be/YAyJGWWgWOo
https://youtu.be/HauHIpBH2mY