How this is anything less than self-evident to all, I don't know. Never ever consent to letting the police search your car. They wouldn't be asking you if they already could. The foreboding tone that they're speaking to you in is just that, a tone. They are not actually saying anything, and as soon as you have the ears to pick that up it's actually very funny.
In all honesty, if being frowned upon by authority hurts your feelings so much as to turn your brain off you really shouldn't have gotten into the smuggling game at all. Maybe you should have stayed at home and gone to work at Dad's hardware store instead. It's a good store, it kept you fed. Now dad has to explain to grandma why you won't be home for Christmas. Was making making officer friendly happy worth the price of making grandma sad? Did you really think you could just smile his suspicion away. You're an outsider. The entire budget of the county which employs him is dependent on finding reasons to lock up outsiders. It's the main source of revenue for every local gorvernment between Omaha and Salt Lake.
Always say no to every search request, out of hand, even if there's nothing in yout trunk except pictures of you training puppies to convert heathens, and none of this would have happened. Who in the hell is hiring these bush league morons to deliver their product anyway?