Well 350Z I am unable to agree with you on this point, cause I have tried myself in DIY way and some of my team technicians who did it proffesionally, can fix them which will remain for minimum 8-10 months and maximum one of our client get his one fixed by our technician, and its there for last 1n1/2 year.It depends on the weather conditions mainly. There is a specific procedure for that.You can also try it yourself at home.
You might have seen that on the chrome accessories ,which we put on various parts of our vehicle like door handles,door end guards,rear lights, bumper corner guards,etc.., they have a thin green plastic strip on the sticking surface of the chrome accessory.Heat that green plastic surface with the hair dryer/blower you may have with you.Use a solvent to clean the body surface of the vehicle to remove all unwanted foreign particles like dirt,grease,oil,etc.get it dry with dry cloth.Then remove the green plastic covering of the sticking surface gently and paste it on the cleaned body surface, press it and again blow with little hot air, now it will be perfect fix which will remain for a longer time.
The strip came out from my client's car as soon as he reached his house after installing it in xenex, that is within 30mins.Even if they dont follow our mentioned procedure still how can it come out so early...so its a question mark on their workmanship
in this procedure you should also ensure that there should not be any trapped air bubbles between the strip and body surface after pasting it.