In the hope that it may save others a bad experience, here's what happened recently to me with these vendors.
I placed an order with thebenzbin.com in July for a muffler and header pipe and it was my worst internet buying experience ever. No email confirmation, took almost 2 months to ship the muffler, which came unboxed and all dented and mangled. Oh, and they charged my credit card at the time the order was placed. Despite repeated phone calls over 2 months, I could never get an answer as to the status of the header pipe. Every time I called it was starting all over with someone new. No returned phone calls and no response to emails either. Finally, calling them again in early Sept, they told me "Sir, the header pipe order was cancelled last week and your money refunded." And how was I supposed to know this?
So, then I place the order for the header pipe with Carstuff.com over the phone. The guy I spoke with looks up the part, assures me they have it and can supply it. I even told him my experience with TheBenzBin and asked if he ever heard of them. Answer: no
Well, a few days later, I go log back on to thebenzbin website to check my return status and guess what? Incredibilly, it now shows a new order, which is the one I placed over the phone with Carstuff. So, clearly these 2 companies are linked.
So, now I get on the phone and call up Carstuff and read them the riot act. Telling them I just went through 2 months of screwing around with thebenzbin and now it looks like I've placed the same order all over again with the same company for a part they can't supply. Carstuff admitted they they did in fact have a business relationship with thebenzbin and a shared order system. Exactlyt what the connection is was vague. He assures me the muffler has already shipped and the header pipe is sitting in the warehouse right next to his building. I ask for tracking # for the muffler and he says he will email it and also one for the header pipe. No email ever comes. Both of these turn out to be lies. The muffler did not ship until days later. They never had the header pipe and finally refunded my money.
The guy at Carstuff told me to email pics for the RMA of the muffler from thebenzbin to snipped-for-privacy@usautoparts.com. So, since the guy at carstuff can process RMA's for parts bought at thebenzbin, clearly carstuff and thebenzbin are linked. Plus, now I have what appears to be a third companies internet address, usautoparts.com.
If you go to the BBB for southern California and check out usautoparts.com, they have an F rating.
I finally got the header pipe from Rusty's MB parts. He told me right away that the header pipe was now only available direct from MB. And he got it for me quickly at a good price.