Don’t come knockin’. Many Americans have a love affair with their car, but a majority of them actually have had a love affair IN their car. A new survey of nearly 3,000 adults reveals that nearly three out of five admit to having at least one intimate encounter in a vehicle. “We didn’t realize just how popular sex in a car is and couldn’t believe how many had lost their virginity in a car,” said George Charles, a spokesman for the online shopping site CouponCodesPro, which carried out the survey . The survey found that 59 percent said they had sexual relations in a car, whether behind the wheel or in the back seat. When asked why? 31 percent responded that, “it wasn’t planned, it just happened.” Another 26 percent said they intentionally “wanted to do something a little bit risky,” while 22 percent said “it had to be the car (because they) couldn’t have sex at home.” But the car of choice may change soon. General Motors has discontinued the roomy Pontiac which was preferred by 11 percent of lovers.