I was checking out Procarparts.com, and I came across THIS LINK.
My DX doesn't have a rear sway bar, and I think the LX doesn't either....so is this an aftermarket sway bar, or something totally different?
I had checked at the dealer, and they wanted around $200 for parts and labor for the rear sway bar...which i think is ridiculous.

That is NOT the sway bar, it is a lower tie bar. NOT A SWAYBAR.

sway bar is the bar thats under the car correct? like it goes from one suspension(rear left) to the other (rear right)?

Ok, my next question is what exactly does this part do for the car? improve handling? Does it make the ride stiffer?

Also...does anybody online sell an aftermarket sway bar kit for the dx/lx? (cheaper than the dealer, naturally)

Be advised ! I wouldn't buy anything from Procarparts.com they got banned from Ebay and there are lots of members that have had problems with them. Search the threads and find out.

Your pic is a lower tie bar. It stiffens the rear end and reduces flex in the frame. Sway bars are attached to the suspension and help limit body roll.

<< I had checked at the dealer, and they wanted around $200 for parts and labor for the rear sway bar...which i think is ridiculous. >>



That is actually a really good deal since all DX's and 2001 LX's and HX's don't come with a rear sway bar. They require several parts and some drilling and welding. I wonder if the dealer knew how much trouble it would be when he gave you that quote?



<< Also...does anybody online sell an aftermarket sway bar kit for the dx/lx? (cheaper than the dealer, naturally) >>



No kit, but read these threads in this order:

RSX rear swaybar installed
WTB: Pics of rear swaybar endlink attachment.
SWAY BAR
More on RSX Sway BarsInstalled RSX Sway Bar Today