I got this from xpert-tuning off eBay. Seller had a good rating and they said this fits a 2016 IS. Installed it today and it seems short - I just centered it but you can see the gaps below. Is this normal? It seems like the spoiler is the width of the window, but there is space between that and the car.

 

I don't have a rear window spoiler, but it seems odd to me.
I would say check out this thread for other window spoilers and decide for yourself.

https://www.clublexus.com/forums/is-...-spoilers.html

 

You know I looked at the site again - seems like the gap supposed to be there. Although mine looks larger. I'll check out that thread too. thanks!

http://www.ebay.com/itm/282214298537

 

your gap is too big, but aftermarket is like that, they never came out perfect, you gotta bend with heat gun a bit.

 

Mine is the same way. I think its the way they made it. It comes from a company called Ikon and at the end of the day they make cheap modification, so you get what you pay for essentially.