where can I buy aftermarket oem lexus fenders the fit good??

 

I dont think they make them, even if they did I wouldnt want to slap one on my car. If you do buy one make sure it is CAPA certified.

You can buy oem used look on car-part.com

Theres two used on ebay right now but only for passenger side.

http://www.ebay.com/itm/2006-TO-2009-Lexus-GS-300-GS-350-GS-430-GS-450-GS-460-Right-Fender-/271333221351?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f2cb863e7&vxp=mtr
http://www.ebay.com/itm/07-08-09-10-11-LEXUS-GS350-WHITE-PASSENGER-FENDER-123373-/350940461351?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AGS350&hash=item51b5ae7927&vxp=mtr

 

aftermarket fenders are very lightweight, and USUALLY easier to dent/ding. From personal experience I'd go with used OEM or some aftermarket FB fenders.