How can you avoid this from happening to your car?
What's the difference between the left and the right?
How do you get from this?
The BEST way to tell if a detailer is competent is to ask them to "SHOW ME YOUR WORK!!!".*
*- The term SHOW ME YOUR WORK!!! is copyrighted by my good friend and fellow detailer KC. You can see him showing off his work on his blog: http://thedetailers.blogspot.com/
All the theory and the best products in the world won't mean a thing if the detailer is not competent and the best way to determine this is to take a look at the detailers previous work.
Have a look at the previous jobs. Take a look at the condition of the paint before and after. Compare the 50/50 shots. How much of an improvement has the detailer made?
Don't be fooled by gratuitous reflection shots. Does the detailer use fluorescent lighting or does the detailer show you shots taken directly with halogen lights or sunlight? Swirls and other such defects are only visible with the proper lighting.
Does the detailer wax over any paint defects or is the paint corrected before being waxed?
Does the detailer charge a flat rate according to the size of the car or based on the amount of work required to achieve the desired objectives? Every car and paint is different and cannot be treated the same every time.
Proper paint correction takes knowledge, experience and patience to achieve. Does the detailer rush to complete jobs within a certain time frame or will the detailer do what it takes to achieve the desired results.
Is the detailer a person hired to do the job or is it done by a detailer whose reputation depends on the quality of each and every job completed?
At the end of the day it still boils down to this...
SHOW ME YOUR WORK!!!