I sold my F30 to our local BMW dealer. Around £900 above WBAC price and no fees or haggling over stonechips etc, although like yours mine was in pretty much mint condition WBAC will always try to knock down their price if possible. I ordered my Tesla in February WBAC was around £16.5K, in March before lockdown just over £9K!!, May time it was back up to £14.5K, I held out and bit the bullet in August, sold at £15800 as I was worried another lockdown was coming. I didn't want to sell private as it's not the time you want strangers to be coming to your house and hassle of test drives and insurance etc, but probably could have got a bit more if I had done.