That sounds exactly like whats wrong, i had new rears fitted a few weeks back and the fronts have about 3mm left. Also the cars been lowered, not sure if that would have an effect? Cant see why it would though..
To the guy who asked they are the normal road f1's.
Looks like new front tires then, thanks
This is most likely the cause. I think the TCS is designed to take into account some degree of tyre wear but obviously it will expect tyres to wear at a fairly even rate. With relatively smaller tyres on the front and larger on the rear to what the TCS expects, it will take a little longer for it to think the rears are spinning faster than the front (ie slipping) and kick in. Personally, I'd prefer it like that as the 350z TCS is quite violent when it kicks in and can unsettle the car more so just go with it.
If when you get new fronts and all the tyres are bedded in it still does the same then we can look at other causes