There are two frequent flyer mile promotions going on right now. Here are the details on the website:

350 bonus miles and up to $20 savings

or

400 bonus miles and one car class upgrade

I'm not sure how many miles one normally earns per day (50? 100?) at this point, I think they just changed the earning rules yet again. But these two promotions are for a straight 350 or 400 bonus miles. And of course you have to pay the extra $2-$3 payola (a.k.a. Frequent Flyer Excise Tax) to get those bonus miles credited to your account.

For that hassle, I just collect ZE 1 (Hertz Award points), which are only slightly more useless than 50 miles per day, but I don't have to pay the stoopid excise tax.