The next time you rent a car from Hertz, you might notice something strange: in addition to the spare tire, first aid kit and jumper cables that you'd expect to find in your car's trunk, there will probably also be a printed trunk liner, covered in garish advertisements.

In case you miss the point, the fine folks at your favorite rental company will reinforce it with advertisements printed all over your ticket folder and further product placements dangling from your rear-view mirror. You might be inclined to wonder if you mistakenly picked up the NASCAR special or, perhaps, hit a billboard on your way out of the parking lot. In point of fact, however, you are merely enjoying the effects of Hertz's latest revenue stream.

The gas crisis has hit rental companies particularly hard. With oil prices regularly setting new records, many people have elected to forgo vacations; even those who have decided to leave town are maximizing their use of public transportation. Added to this, the increasing cost of gasoline has pushed the high price of rental-company fill-ups into the stratosphere. Eager to preserve its customer base, Hertz has already done away with its high-priced fill-ups; nowadays, people returning Hertz rental cars with empty tanks can expect to pay market rate for their gas. Even this customer-loyalty move, however, hasn't been enough to help the rental company weather the gas spike. Consequently, the company has followed the lead of many airlines and is using every available opportunity to sell advertisements.

As far as I'm concerned, if it helps Hertz keep the prices down, I am happy to have my suitcases co-habitate with ads for Reese's cups and Geico insurance!

Bruce Watson is a freelance writer, blogger, and all-around cheapskate. He's wondering how much the rental on an Oscar Meyer Weinermobile would be.