Direct answer: measure automotive AI voice performance as a stage-separated funnel — eligible calls, answered, qualified, transferred/resolved, appointment requested, confirmed, show, outcome — with quality review on both successful and failed calls.
Do not blend stages
Vendor claims often combine "appointment requests" with "bookings." Insist on separate numerators and denominators for each stage and a stated observation window.
Quality measures
- Factual accuracy against approved knowledge
- Disclosure and recording compliance in sample
- Tool success rate and alert timeliness
- Transfer completion, not attempts
- Caller correction and repetition rate
Baseline discipline
Pull 60–90 days of phone data before launch. Without a baseline, you cannot prove recoverable missed calls or honest lift.
See the measurement dictionary and pricing/ROI framework.