In the 00s, my dad had an issue with the infotainment system of its Peugeot 407 that would no longer boot.

An official Peugeot mechanic told him that it would cost something like 4200€ to replace the unit, so he asked me if I could have a look.

After a quick search, I found an update for his system, burn it on a CD, and put the CD into its car.

The system updated, and then would work normally. Problem fixed for one hour of my time and a CD.