Earning Rapid Rewards credits through rental cars is certainly worth it, especially when you take advantage of the promotions listed throughout the stickied thread at the top of the forum. Rental car-earned credits have been key to earning my Companion Pass every year except this year.

All rental car companies charge the frequent flyer surcharge if you opt to earn credits/points/miles. Apparently all companies have recently increased the surcharges and Dollar is the most egregious.

In my experience Hertz is the most reliable Rapid Rewards rental car partner with respect to honoring and posting multi-credit promos.