Forza Horizon 2 will have better legs.
That's all I can say.
FW sales- I dunno.

Forza Horizon 2. Forza is an established franchise and Driveclub's PS+ edition will definitely cut into sales.

DC is tracking above NBZ2k15 AlienISo in most Euro markets and even Shodow of Mordor in quite a few of them.  Amazon can be very effectivly used to guage intrest, especially when comparing to games releasing in the same time frame.  DC is doing very well in Germant Spain Italy, logically rest of Europe will follow suit as PS dommantes there far more then elsewhere.

I personally hope it does well, but I'm not very optimistic about it.

Forza.

Updated OP with results!

I'm actually shocked Driveclub did better, especially with its horrible launch.

#DatBruteForce

There are simply more PlayStation gamers, and as it turns out all gamers want to game.   I think a DriveClub victory was alway the most likely outcome.  It is a shame that the lauch was botched, but that being said, its hard to overcome a 2:1 deficit when comparing games on a WW scale.  

I'm quite surprised that Driveclub outsold Forza Horizon 2, if numbers are any bit true.

True and the PS+ edition didn't launch so I expect some people probably jumped the gun and bought the game instead of waiting.