i'm assuming support for the mugen is pretty good in
your area since you own the sedan. So just make life
simple and get the mrx3, it is very similar build as the mtx3
as far as drive train and shocks the main difference is just
the quick release for the wheels.
as for the mrx4 that rumor has been out for a while now
if you can wait indefinitely.
TQ-racing Yokomo BD7 Airtronics