RockAuto also has what some might consider a "dated" interface, but honestly it's light years better than trying to use NAPA's or CarQuest's website or god forbid looking through dealership parts counter websites. I honestly wish regular retailers would have stuck more closely with what worked for more B2B focused ecommerce, i.e. I wish shopping Best Buy or Home Depot was more akin to McMaster, Fastenall or some of the nicer supply house web portals.
Sadly Sigma-Aldrich, the hyphenated retailer for chemistry, appears to have been covered in javascript sludge.