I changed the oil for the first time today on our new to us 2016 Nissan Quest. In the process of removing the plastic clips for the engine splash shield that covers the oil filter, one of the clips got away from me and I can't find it. She's back on with 3 clips at the moment. Not being sure how to measure the darn things, anyone off hand know the size so I can mail order a bag of them? Thanks. Yes I spent about 10min searching this site.

You mean rivets like these http://www.ebay.com/itm/291985389203 ? It's 8, 9, or 10 mm. I get mine off the eBay, search for plastic rivets. I got bags of 100 in like 8 and 9mm sizes and they fit both Honda and Nissan. Can't remember or tell which size fit, as I randomly opened one bag and it fit right away.

There are actually 2 different lengths used around the engine bay and splash guards etc. These from the eBay are closer to the short one, but they still fit the holes occupied by both long and short Nissan rivets. And the eBay rivets are better, they have a threaded center pin which is easily removed with a Phillips screwdriver vs pulling the Nissan pin with pliers/flat screwdriver and breaking 1/2 of them in the process.

Yep. Push-pin retainers, rivets, clips, push plugs, plugs.. What ever the proper name is for them. The (I assume) factory ones on my 2016 have 3 notches in the head that are spaced 120deg apart, making them tough to grab with the push plug pliers I have. I popped the heads out to release them with a pick with a 90deg hook at the end. Of course one shot out, went flying and bounced around off stuff under the van and came to rest somewhere. I have yet to find it.