I guess the speed was restricted so that an over-enthusiastic driver doesn’t loose the roof when exploring the the extremes of the performance envelope. The Vantage Volante shares all the exterior features of it’s closed brother. The V12 engine (in stage 1 tune) needed more cooling air than the 6 cylinder and so the trademark Aston grille was enlarged. This meant the creation of new indicators and driving lights which were moved to a new position. These units are reminiscent of features on both the Project cars (DP212, DP214 and DP215) and the DBR1 race car.
Total production of the DB7 Vantage Volante reached 2059 examples, only a fraction behind the number of coupes built.