Yes! There are many car rental software available online.
Among them, I recommend you QoreUps.
QMarket is a SaaS marketplace software where you can start any type of rental marketplace.
QMarket provides unique and advanced features to make your car rental business more user-friendly.

1. Multiple Booking, Payment, Language, & Currency Options.
2. Real-Time Analysis
3. Cancel & Dispute Function
4. Site Management Options
5. Business Management Options
6. Marketing Management
7. Advance Search Filter
8. Custom Domain

The reason I strongly recommend QMarket is that it is a ready-to-go platform that helps you to launch your car rental business within 5 minutes.
Along with this QMarket provide a 30-day free trial to explore their product. Additionally, QMarket provides excellent customer support, ensuring that you have everything you need to get started and succeed.
They also offer customization options, allowing you to tailor your car rental software to your specific needs and preferences.
So, check out QMarket to know more about their offerings.