The dog days of August may have motorists reaching for the air conditioning switch in used cars in New York, and they can now do so without worrying about fuel economy.

Industry scientists say that for sedans, the aerodynamic drag caused by rolling down the windows at highway speeds robs a vehicle of more energy than putting on the A/C.

To make the process more efficient, air conditioning subunit manufacturer Delphi recommends that before starting up a car that has been out in the sun, roll down all the windows to allow hot air to escape, then roll them up and put on the A/C.

Proper maintenance may also help owners cool down in used cars in New York: air filters can become clogged and less efficient, pushing less cool air through vents to occupants. Old coolant may also cause a similar reduction in the effectiveness, noted Delphi.

In city driving, however, SUV and truck owners may want to consider not using the air conditioning feature, since the boxy shape of those vehicles will outweigh any fuel savings, reported Slate.

When people consider their options when looking for a newer model vehicle, one possibility is to donate used cars in New York to charities. Owners get a tax break and charities profit from selling their stocks.

Unfortunately, the nonprofits say that the Cash for Clunkers program has had a negative effect on their ability to raise funds for initiatives like housing and feeding the homeless, which is the aim of Mission Solano in California.

“Those profits were already down as consumers hold onto old cars longer or broker their own sales to weather the bad economy,” says Ron Marlette, the organization’s executive director. “But, the Cash for Clunkers program is also hurting those who traditionally turn to the Mission to buy low priced transportation.”

It also hurts the prospects of those who may want to buy used cars that are within their price range, but are unable to do so because the vehicles are now marked “Not for sale – must be crushed,” he added

Further east, some charities in Chicago say they will be lucky to have sales reach 25 percent of their height, according to CBS News.

Some in the industry estimate that up to one in seven motorists drive without insurance, but new enforcement efforts could affect owners who choose not to buy policies for used cars in New Jersey.

Local police agencies are setting up checkpoints that are similar to DUI stopping areas, requiring that drivers prove they have insurance and registration documents.

And it really doesn’t matter who they stop. William Mecke works for the Georgia Regional Transportation Authority as its communications director, and actually has insurance.

However, when an Atlanta-area officer stopped him and asked for proof of insurance, Mecke couldn’t find a current card and ended up with a ticket.

For those who choose to go without insurance entirely, police have the right to seize used cars in New Jersey and other jurisdictions, levy hefty penalties and even suspend someone’s license.

College students may be one group more affected than others, with lower annual income than other demographics.

They could help themselves two ways: a fuel-efficient used car is often less expensive to insure than new models, and getting good grades can reduce rates as well.