Should I use it in the Gran Turismo All Stars? Seems like an okay car. I checked out stormbringer's list of the best cars and I'm convinced that I could use it if i hopped it up a bit.
Possibly, I used a JGTC Supra with 600bhp and soft racing tyres, that weighed 1100kgs, so I guess a maxed out R390 road car, set up for each track and diriven fast and consistenly should be able to do it.