I use the Logitech Driving Force Pro on my PS2, and I left foot brake a ton in GT4.
That lap was quick simply because I was able to keep my speed up pretty well in all the corners (especially the left-hander under the bridge onto the back straight). However, my line could have been improved upon in all the corners (especially the left-hander under the bridge onto the back straight). I ran a few more laps to see if I could best my time, and I think I was able to go through each corner faster than the ghost, but just not all on the same lap. I even had one where I was ahead into the final corner, but then got passed by the ghost right before the finish line (+0.002)

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Anyway, let me know if there are issues w/ the next challenge. The car is very "point and shoot" and easy to drive, except for it's ability to break traction easily on hard acceleration... since a lot of the corners at Monaco are very tight, keep in mind that short shifting for traction is probably a good idea in some spots.
That Lister is a howling banshee too.