Which one to convert depends on several factors:
1) Both are great cars and very competitive. ie: both can do 2:12 on akagi down dry.
2) Which car has more points? I beleive full tune version 3 would be 2 million points. That is perhaps becuase there are more courses now to race on. So you would like to use the one with more points and transfer. Can save some money.
3) Which car has the LOWER battle level? Because from what i heard, after you transfer to version 3, your battle level is not kept. ie: go back to 0.
4) Then again, you can just keep both at version 2. Use the Rx8 in version 3 or maybe, there are even more tunes to choose from with the Rx7s in version 3.
Hope this has helped.
