Right - it only works on one vehicle at a time. If you plug in the AP to Car A, it gets "married" or locked to that vehicle. You can upload maps, change things, etc all day long until kingdom come. But if you plug it into Car B, it will not work. You must unmarry (divorce?) the AP from Car A - which also means going back to stock tune - before it can be used on Car B, at which point it is 100% functional in perpetuity for Car B.
E92 335i/6MT Dinan Stage 3: intercooler, oil cooler, intake, flash, exhaust, LW dual-mass flywheel.
Vishnu PWM methanol custom trunk mount, Diffsonline 3-clutch Salisbury custom diff, Ohlins Road and Track coilovers, Vorshlag camber plates, much more...
E28 M5 w/ buncha stuff, R171 SLK350