Buyer Beware: Hiley VW Service
I wanted to share my experience because I fear anyone less knowledgeable may fall prey to the tactics described below.
TLDR: Hiley VW insisted my brand new battery was faulty, without evidence or reason, simply because I replaced it and refused to do any work until I decided to replace the perfectly fine part for $366 (on top of the diagnostic I wanted).
Full story:
I brought my 2015 Passat SE here for intermittent starting issues and wheel speed sensor codes. Before bringing it in, I installed a brand-new, fully charged battery, which improved but did not fully resolve the starting issue.
Instead of performing diagnostics, the service department demanded I buy a $366 OEM Volkswagen battery on top of their $205 diagnostic fee before they would even begin. When I asked for proof that my new battery was faulty, they insinuated that because I changed it myself, I likely "damaged the ECU" or "put it in backwards" (which would have caused an immediate fire). This intimidation tactic allows them to guess at repairs rather than diagnose them.
In reality, the car started 100% of the time with a jump pack, proving the ECU was perfectly fine. They refused to consider known starting issues for this model year and falsely claimed they couldn't diagnose the wheel speed sensor without a new battery.
When I stood my ground and required data or evidence of damage before permitting the battery work, they refused. They easily could have run a starter amperage draw test, a voltage drop test on the ground cables, or scanned the sensor via VW ODIS software. Once they realized they couldn't exploit me, they suddenly backed down, waived the $205 fee, and told me to pick up my vehicle.
They clearly used common tactics to push unneeded parts and labor. They refused to actually test my battery because doing so would cross the line into auto repair fraud. If you use this department, know your rights, demand hard data, and never divulge that you did your own minor maintenance.
To make matters worse, my wife bought her car here and has to constantly babysit them just to get callbacks for warranty appointments. The sales team was fine, but we will be driving to Chattanooga for any future VW needs when her warranty expires.