mine popped out...it was on the garage floor. i didn't realize what it was....held on to it for a bit. finally, gave up, threw it out. 2 weeks ago, i was making sure they changed the brake fluid as i paid for that as well as the tire rotation and such. next thing on the my list to do was change the transmission fluid, so i looked down there and no plug. i was like, wtf! i immediately thought the dealer had forgotten to put it back on when they did the comprehensive multiple point inspection few months back. i couldn't prove it, so i had to buy it myself. i got on line, looked up the part and then i realized that was what i threw out in the trash. it had popped out in my garage. i called to get a new one...it ranged from $17 to $26 at various dealerships. the parts lady asked my name and noticed i had just been in there recently, a few times. i said, yes, and the next thing i was going to do was the fluid change. she told me she's order it and no charge for me and to have me come pick it up. how nice of her. that's how you keep customers, in my mind.
anyways, this seems to be an issue. i'm thinking of rigging a safety wire to the new one so if it does pop out, it won't be lost.
but first, i have to get the front end repaired...got tagged Sunday morning. 17 yr old kid in '06 civic going way too fast in the snow and lost control and slammed into me. he was trying to turn right, as i was leaving the neighborhood. dash cam proved to be useful to the police!