SixthGear

Team Logo
App screenshot

Inspiration

Car rental customers often face long queues at checkout, a frustrating, time-consuming experience. While in-app checkouts help speed up the process, they miss a critical revenue driver: human-like upselling. Real sales agents excel at empathy, timing, and personalized recommendations, which static digital flows fail to replicate. We were inspired to close this gap. Using realistic AI avatars, we combine the warmth, trust, and conversational nuance of a human agent with the convenience of a seamless, queue-free, and instant mobile checkout.

What it does

SixthGear processes a customer’s full rental booking end-to-end. It:

Validates the driver’s license
Guides the customer through a fast digital checkout
Holds natural, friendly conversations about the customer’s trip
Recommends personalized upgrades (car class, protections, addons)
Explains each suggestion with helpful reasoning, just like a human sales agent The experience feels like talking to a human sales rep… but instantly, anywhere.

How we built it

We combined Beyond Presence’s hyper-realistic AI avatars with:

OpenAI Speech-to-Text and Text-to-Speech
LiveKit for real-time audio/visual interaction
GPT-based state management to transition between sales stages
A custom decision-making engine for protection and addon recommendations
A FastAPI backend connecting directly to Sixt’s booking APIs

Challenges we ran into

Surviving on 4 hours of sleep in 2 nights
Integrating LiveKit into our custom frontend
Keeping avatar responses natural while managing strict agent states
Getting consistent reasoning from LLMs despite their nondeterminism
Ensuring high-quality, human-like upsell conversations, maintaining speed and accuracy

Accomplishments that we're proud of

Pulling through, making it work finally after many struggles.

What we learned

Read the API Documentation carefully
Don't be too adventurous in using new libraries at a hackathon

What's next for SixthGear

Video integration and image segmentation to learn more about the customer visually and tailor the conversation to what we see.
Noise-cancellation for more robust service in busy environments like the airport.