It will show up, however you have to dig deep to find it! I am a tech for Mercedes and i know loads of cars that i have worked on have been remapped, however it can be very hard for the average technician to find! And to be honest... I don't worry if the car had been remapped or not, if there is a fault, i will just fix it!
I had an sl55 amg that had all different pulleys and remap and was pushing 620Bhp and he blow the diff to pieces, but i still replaced it for him! It will all boil down to how fussy the tech is!