Bowers&Wilkins ASW675 10" Sub, blown driver. Can't find anyone to repair it.

How old is this sub?  Who replaced the amp?  Where are you located?   I had to have my ASW-610 repaired this year.  It was shipped back to B&W in MA by my local audio store.  The main circuit board had to be replaced.  If parts for your ASW675 are no longer offered by B&W, then yes you will be facing a challenging situation. I found the following link on-line.  This is a list of authorized service centers for B&W/Rotel for warranty work.  I'm sure your closest dealer would be happy to take a look and offer a repair for $$ if they have or can find a replacement driver.  http://bwgroupsupport.com/service/service-centers

" Does anyone out there know of someone that might be able to help?"

You're dealer. They should be handling stuff like this even if the speaker is out of warranty. If you take the driver out and find that its not soldered, you can just replace it yourself. And if you know how to solder, its not hard at all to do. 

B&W is just crazy with issues like this because they think mail order is somehow involved. They would rather piss you off and lose you for a customer, than to help fix your speaker. The last pair I had, B&W did me a really big favor by allowing me to drive 150 miles to a dealer and sell me an x-over for a speaker that was still in warranty at full list price. Why? I moved to an area where there was no B&W dealer, so I had to be punished.

My ASW 650 stopped working a few years ago, I called B&W support (in L.A.) who told me to extract the amplifier module and send it in. Instead, I opened the unit (not exactly easy but still doable) and took the fuse to a service shop for a replacement. That did the trick!
P.S. Always use caution servicing electrical equipment.