Research and writing what you know...

Have you ever read a book and thought, "Wow! This must have taken tons of research"? I've done that many times, especially before I became a published author. It only recently occured to me how much research I do, some without even realizing it. It'll bet you do too.

"What, me?" you ask. "But I don't write."
Even if you don't write, your research is all around you. Do you have a favorite restaurant, a favorite grocery store? It's because you researched and found them. Every time you Google, you're doing research --research that can be used in a story. 
I've done some crazy things in the name of research, from joining a dating site to standing in a closet, trying to figure out logistics for a love scene. A good friend and fellow writer actually visited a car dealership to crawl into the back seat of a Mustang while writing an abduction scene and wondering how much room her protag had, how he was laying, how much he could see, etc. But again, some of my research happened without planning. I've even got a story that began as personal notes when I vacationed in Hawaii. 
Any experience can be a story, even a trip to the laundromat, 'cause hot, hunky firemen would have to go to the laundromat, right? And what if a nerdy college student bumped into him while reading a calculus text? See where this is going? Knowing where the washers are in relation to the dryers, where the drink machine is, etc., helps you to craft a believable story, or helps you visualize what you're reading. 
Diversion began as a few articles I'd read on pharmaceutical drug crimes, the key plot points practically knitting themselves together. My current WIP is the same. But how much is too much? I must admit that I watered down facts in Diversion, because the truth seemed very farfetched, even to me. So Lucky's time stealing a truck became five minutes, when the actual time, based on a true case, was two and half. I wasn't sure anyone would believe two and a half minutes, so I lengthened the time, and I cut the dollar value of the heist. 
In Collusion, the sequel to Diversion, I've again based the story on actual events happening in the US that most people I've bounced the idea off of didn't know existed, like a critical drug shortage that's forcing doctors to break the law and order illegal imports just to serve their patients' needs. "No doctor would do that!" I hear. Oh, yes they would, a known seventy-nine total to date since the crisis started, which brings me to my dilemma: what is more important, the truth, or believability? And where does good research cross the line, ripping a reader out of the story?
Thoughts, anyone?