The best way to get the best possible deal on a budget rental car is to book your ride early, and then check back frequently to see if the prices have dropped. The fact is that most rental car companies run frequent promotions and there’s a lot of price volatility, especially as you approach holidays. The nice thing is that almost none of them charge you a cancellation fee, so if you find a lower rental rate elsewhere, you won’t face a penalty for canceling and rebooking your rental car at a lower price.