  We present accurate simulations of the dynamical bar-mode instability in full
General Relativity focussing on two aspects which have not been investigated in
detail in the past. Namely, on the persistence of the bar deformation once the
instability has reached its saturation and on the precise determination of the
threshold for the onset of the instability in terms of the parameter
$\beta={T}/{|W|}$. We find that generic nonlinear mode-coupling effects appear
during the development of the instability and these can severely limit the
persistence of the bar deformation and eventually suppress the instability. In
addition, we observe the dynamics of the instability to be strongly influenced
by the value $\beta$ and on its separation from the critical value $\beta_c$
marking the onset of the instability. We discuss the impact these results have
on the detection of gravitational waves from this process and provide evidence
that the classical perturbative analysis of the bar-mode instability for
Newtonian and incompressible Maclaurin spheroids remains qualitatively valid
and accurate also in full General Relativity.
