We will be traveling thru the Greek islands with a leased car. Will Turkey allow us to bring our leased car from a Greek island? Our leasing car company does allow travel in Turkey.
You can bring a rented/leased car into Turkey for up to 6 months. You can find the regulations here: http://www.gumruk.gov.tr/ENG/traveler/RoadVehicles/Pages/default.aspx Assume you're aware that the only Greek islands that have vehicle ferry service to Turkey are Chios, Kos, and Rhodes.
Check to be sure your leasing company will allow you to take it on the ferries - some car rental companies will not (or disallow the insurance). We liked having a leased car, but I have to admit, I wouldn't want to go that route on the Greek Islands - too expensive to take a car from island to island.