Since I disagree with Gran Turismo's "let's offer returning cars as 'free' DLC", I'll have to point out the Karmann Ghia and the Type 3 sedan aren't the hottest of additions. It feels as if Playground didn't have time to make these cars ready before release and is releasing them in steps... Provided you play the game of course, otherwise you'll just get shafted.
I seriously hope the Karmann-Ghia has either the 914/6 or the Carrera RS engines available as swaps! No GT3 RS nonsense, though you could still have it "for the lulz".
The Astons are solid additions, though. I really wanted to drive the new DBS and the Shooting Brake is a nice companion to the GTC4 Lusso.
Somehow I feel as if FH4 isn't the game for the Performante and the Pista. Both of them would start in S2 already. They'd be in a similar situation to the GT2 RS, which you can't race competitively without radically changing the car itself. Or even the Corvette ZR1, which was gimped when it comes to upgrades.
Still, Forza used to go out of its way to feature the latest and best. Remember we just had a VIP DLC filled with similar cars in FH3... Considering the Huracán Performante and the 488 Pista came out a while ago, I'd have expected to see them added to Forza at this point. The VWs feel like a token effort in comparison, all they did to them was add wider track and new engine swaps (possibly).