I'm a noob at this forum. But I couldn't find any info. Does anyone know if we can buy a OEM spoiler for the sedan without a sports package? If so, do you know the part number? THANKS!

Any dealer can hook you up with a spoiler.
Painted and installed would be around $600-

You can get a knockoff from eBay... looks like OEM, but is only about $150 and comes painted.
It does require drilling holes in your trunk lid and a little wiring, so if you are uncomfortable with the thought, you'd also be looking at installation costs.

As the above poster said, check out this : http://www.spoilerdepot.com/Catalog.asp?idMake=10&chrMake=Infiniti&idB=
They make a replica OEM spoiler for a lot less money and it is painted. People have given good reports on these spoilers

Thanks guys. If anyone still knows the OEM part number, please let me know! But as for the spoiler from spoilerdepot, even if I get it added on should I be worried about the wiring since I have the nav package which has the backup camera, so if my mechanic accidently drill a thru a wire, I'll be screwed?

Nope, wires are extremely easy to repair once severed or broken.

NO worries with wiring. It is pretty basic.
The OEM spoiler will cost 3-4 times the price. If you want the OEM Part # , just call a Infiniti Dealer Parts Dep't

The dealer installed mine, it's an aftermarket OEM, looks just as good as the factory spoiler, not sure of the cost though, they threw it in as part of the deal.