can we used custom SEO URL in product cart?

I don't see any justification whatsoever to balance pretty much nill benefit for all of the agony it would take to do this either through ISAPI rewriting or by doing such a major overhaul on PC (which would leave the application in a state that would also be very expensive to maintain updates).

Show me a really good reason this should be done (what huge benefit would accrue?), and I could be pushed towards using ISAP_Rewrite to do it, but the regex is very tricky and prone to cause headaches.

BTW, if you were to do this, you'd want /About-Us/ as your faux directory.

Rewriting away the /productcart/pc/ directories is easy (I've a thread on that here and do it regularly with stores hosted on our servers -- though we've gotten bitten by it a few times). EI claims there's no SEO benefit to this, and SEO's are never decided with any consensus on anything. I just find it to be a "prettier" URL. Same argument could be made for your request, but what's involved is not worth the pain simply for aesthetics, IMHO.