I was thinking about trading my FG 2011 FPV GT in on a new 2018 Mustang GT 5.0 Ltr but have the following reservations, a) no spare wheel/tyre is supplied on the Mustang, b) only a 3 star safety rating whereas mine has 5 stars, c) no options yet for a Supercharged V8 motor. And even though my vehicle is in showroom condition I can imagine getting offered a lowball trade-in figure. Should I wait for the 2019 models before deciding or just keep what I have?