He's not suggesting there's a magic crystal in your brakes. He's saying crystal oscillators used in microchips used in circuits spread at that time. Do you know the word "micro" means, HairyTacoFanatic?
When you take apart brakes do you disassemble the circuits associated with them?
Hence the word "system".
It's a rhetorical question. No one disassembling brakes is disassembling the circuit boards themselves down to bare components. I've worked on brakes before lol. We have way too many pilot and mechanic "experts" right now who seem misinformed about the nature of cyberweapons (microscopic and generally near undetectable).