Every car of a given trim starts with the same template twin. What makes it personal is a calibration loop that runs quietly in the background of ordinary driving, nudging dozens of physical parameters until the model's predicted behavior matches this specific vehicle's measured behavior.
Not every parameter can be identified from every driving style. A car that never leaves flat city streets provides little excitation to estimate high-speed damper characteristics, so the calibration pipeline tracks a per-parameter confidence score and widens its uncertainty bounds for coefficients the owner's actual driving has not sufficiently excited, rather than silently reporting an overconfident guess.
If a technician replaces worn shock absorbers with new ones, the twin's carefully converged damper parameters instantly become wrong. The calibration pipeline listens for service records and odometer discontinuities in workshop diagnostic sessions, resetting only the affected sub-model's parameters and their confidence scores to factory-default values while leaving the twin's knowledge of every other untouched component intact.