How likely is it that you will get paid more than the initial evaluation from companies like Motorway and Carwow?
When I sold my 458, I tried Motorway and they came back saying 117k.
The best actual offer was 105k.
Then a few days later a Ferrari dealer rang me directly offering 110k, so was obviously one bidding on Motorway, so I guess it can be worth putting a car on these platforms, just make sure you have the car also advertised on say PH/AT with an easy to identify photo, so then they can call you directly with a better offer, no doubt also means they don't then have to pay a kick back to likes of Motorway etc.
In the end I sold the car privately for 126k, so patience paid off.