Very positive review of WRC4 from Pocket Gamer. I've been playing WRC3 a bit more lately and yeah, career mode will pretty much fix it for me. Handling and game player are already pretty damn good.
http://www.pocketgamer.co.uk/r/PS+Vita/WRC+4+FIA+World+Rally+Championship/review.asp?c=54917
It's also been reduced already on ShopTo to £24.85 so I'm currently feeling really tempted to grab it already >_