User blog comment:Visually/RnD is hard and expensive. But you can do it only for rewards./@comment-92.238.46.151-20151022205533/@comment-26536836-20151023072036

I think you can check out from Martin Kneip's document in google+ Asphalt 8 communities.

He made this https://plus.google.com/105163125232014941976/posts/g788ughYpLR

It looked like so many information but I saw there has rewards, too.