So, an R33 GT-R is $18,000. If you wanted it to be, say, a GTS model with a swapped-in RB26, would you have to pay for the RWD conversion? Just asking, as it would break the fantasy-sense of the game to say you bought a GTS-T, and then had it converted to RWD via your bank statement/build list.
The same question applies to all RWD models of AWD cars, like R32s, R34s, and anything else, like XR4Ti versions of the Sierra and the like.