I have had both manual and auto cars, but at the time of sale in my case it has not made any difference. I know certain makes and model must have an auto box come resale time, however you will always find that someone prefers a manual, although I admit with the increase of autos that is likely to decrease. When it's time to sell it is nearly always a lottery on price being offered anyway. It's up to you but I went for the manual this time because it's a good box and I was wary of getting the new auto in case of issues with it, but that was just me being a bit paranoid