RE: fg mt any prob's ?
I'm pretty satisfied with mine. They aren't indestructable, far from it - but all in all they hold up pretty well. Some things need changing right away though, the shock oil being the most important one. Go with a leaner oil as mentioned earlier.
A reinforced diff-tube is also recommended, it will keep the diff-gears intact when small rocks decide to join the party and get squeezed in under the diff. Which they will!
Another good thing to remedy is the first gear-wheel - the original one of plastic will wear down pretty fast - and getting one of steel will increase the lifespan considderably.
Those 3 things are right on the top of the list. Everything else you can do does not correct design flaws, but rather adds to an already solid "toy car" which isn't prone to breaking down often.
And hobbythek is _the_ place to order an FG. Service is top notch. Although german based their English is quite good, so go on give them a call if you have any questions regarding purchasing an FG.
Cheers