Quick breakdown:
Traditional: you fill out a form, and a tune is based on your specifications on an ECM/TCM, modules are mailed to you. You will need to find a shop to perform the crank relearn
Scan Cable: you rent a cable to datalog with, you email us the datalogs along with your specifications, and a tune is built on an ECM/TCM, modules are mailed to you, you use the scan cable to perform the crank relearn, you gather another log to verify the tune in the vehicle. Once all looks good, you mail back cable (and stock modules if you desire).
AutoCal: everything is done via email, you use the AutoCal handheld to collect datalogs, email the logs in with your specs, we email you your tune, you load to the AutoCal and flash to your vehicle. The AutoCal is yours to keep, and can be used as a code reader as well as to tune other vehicles (up to 8).