Go on a rainy Wednesday. Know your target price going in and stick to it. Helps to have your ideal price in your head and what you'll settle for. I usually keep to my ideal price. If you know you have other options and aren't tied to that vehicle, you have more leverage--especially if they sense you'd LIKE to buy their truck, but you are willing to walk if needed. They have a bottom line considering what they paid and the fact they need to make a profit. It's much harder to know what that is on a used vehicle though Good luck!