  We present autoionization spectra of metastable Ar(8+) and C(4+), N(5+),
O(6+) and Ne(8+) scattering off an Al(111) surface with incident energies down
to 5 eV. The unprecedented quality of the experimental data permits the
observation of a unique, yet undiscovered peak in the structures originating
from the metastable projectiles compared to corresponding ground state
configurations. Analyzing the peak positions for different projectile species
and velocities we demonstrate that the peak must be ascribed to an
above-surface transition under participation of the metastable state.
