Like many travelers, I’m a big fan of car rental booking site AutoSlash.

9/10 times AutoSlash will find the cheapest rental option, and 3/10 times it is substantially cheaper than comparable sources (estimate, not scientific numbers).

But AutoSlash failed me recently.

In booking a 6-day rental in Pittsburgh, the cheapest option AutoSlash found me was a $360 option from Dollar.

I booked that option 10 days ago, and AutoSlash still hasn’t found and sent me any cheaper options, as they usually do.

Out of curiosity this week, I checked my GF’s Chase Ultimate Rewards (UR) travel portal to see what rate she could get using points from her Chase Sapphire Reserve credit card.

I was surprised to see that Chase had actually found a rate that was not only cheaper, at $300, but it was with a company I prefer, Hertz.

Since UR points are worth 1.5 cents each in Chase’s travel portal, we booked the Hertz rental for 20k UR points.

Chase lets you pay in as many or as few points as you want:

Lesson learned: if a rate seems too high, check your travel portals.

Now, two wins from AutoSlash.

1. AutoSlash posted an article recently that explains two things: Car rentals booked with car rental points don’t cover tax, so those “free” rental days can end up being nowhere near free. Also, the amount of tax you pay per day varies wildly depending on the location you book for, so choose where to spend your points wisely.

Check out the per-day tax charges AutoSlash found at the busiest airports:

Screenshot from Autoslash.com.

I almost have enough Hertz loyalty points to start looking at booking a “free” car rental for the first time, so this info was interesting and helpful to me.

2. Another fascinating tidbit AutoSlash taught me this week? American Express Platinum cardholders can get a free 2-day weekend rental per six months from Avis, by completing two paid rentals in each six-month period.

I don’t yet have a Platinum card, nor do I ever rent from Avis, but this is something I’d never heard about that could be valuable for Platinum-holding Avis renters.

If you are a Platinum-holding Avis renter, please comment below. I’d love to know you exist.

*Update 7.14: AutoSlash found my post and commented on Twitter: