If you're looking to buy a car, here's when to do it.

Ever heard the adage that you can get a better deal on a car if you buy on a rainy day? Or what about the one that says you'll have more bargaining power if you walk in the door 15 minutes before the dealership closes?

"People love to speculate but it's silly," said Phil Reed, senior consumer advice editor for Edmunds.com, an automotive research website. Industry statistics show neither wives' tale is true.

It is possible, however, to time your purchase to get the best possible deal. The end of the month is always a good time to buy because dealers are eager to reach monthly sales quotas that can translate into big bonus money from the manufacturer.

"Manufacturers will tell the dealer, ‘If you sell 20 Camrys this month, we're going to give you $500 extra per car.' That's $10,000 more for the dealer," explained Jesse Toprak, vice president of industry trends and insight for TrueCar.com. "If he's sold 18 so far, you know he's going to push hard for those last two." That means he'll be more willing to negotiate and you can walk away with a great deal.

That's especially true in December. Carmakers and dealers are always eager to finish the year with a strong burst of sales to pad the year-end figures and also to give them some momentum heading into the generally slower winter months. Plus, dealers are anxious to get rid of leftover cars from the previous model year.

Instead of going out to party on New Year's Eve, you might want to go car shopping. According to TrueCar.com, Dec. 31 will be the best day to buy a car this month, with an average 8.2 per cent discount off the manufacturer's suggested retail price. Generally speaking, the later you wait in the month, the better the deal. The downside of waiting, however, is that the inventory is picked over, especially cars from the outgoing model year, so you need to be prepared to act.

Right now, 2010 models are being heavily discounted as dealers try to make room for the 2011s. Chevrolet dealers, for instance, are offering $4,500 incentives on the 2010 Silverado pickup. Competition is intense in the pickup sector as the economy slowly rebounds, so you can get an entry-level Silverado, with a regular cab -- a great work truck -- for as little as $21,670. That's a 17 per cent discount off the sticker price.

There are even some good deals on 2011 models, like the 2011 Mercury Milan mid-sized sedan. Any time a carmaker kills a brand, owners start worrying about things like service and resale value. Ford Motor is shutting its Mercury division after the 2011 model year, but Ford isn't going anywhere, so service will still be available.

If you're in the market for a small car, the 2011 Nissan Sentra is "an amazingly good buy," according to TrueCar.com. The Sentra 2.0 typically sells for $15,398, but with a $2,500 Nissan incentive you can get it for as little as $12,898, or 16 per cent off the sticker price.