Richard,I have decided to take my car to European Performance, in Raleigh, and have them sell it on consignment; mostly because I will be traveling a lot in the next few months. They will do a few things to get it ready to sell, then put it on their lot and website. I'm not sure what the asking price will be: I've just set a minimum, and will let the professionals go from there. Here's their website: https://www.europeanperformance.net/
They've had good success using BringATrailer auctions including an E39 M5 last year. Perhaps they'd be willing to manage the auction for you. I'm guessing it would bring the highest return going on that site. I was very happy with the process of selling on BaT. The only issue you'll have perhaps is BaT wanting your reserve lower than you might like given the mileage of the car as they want cars to sell, so higher mileage ones they either want a generously low reserve or no reserve for the most part.