Yes, he can. Yes, he will. My advice to you is to not keep your weed in your car if you can help it and to hide it extremely well if you need to. Most cops won't have a dog with them so if you hide it in something or somewhere completely inconspicuouse (for example, inside a glove rolled up inside its counterpart in a backpack...for small bags. He'd likely look in the pack, but inside the gloves like he's going to check inside every little nook and cranny. If he did he'd be looking for an hour and he has other shit to do!)