The authors have investigated multiple electron capture into autoionizing projectile states during 108 keV Ar9+ and 80 keV 13C5+ collisions on Ne by measuring autoionization electrons in coincidence with charge state selected target ions. They have determined partial electron energy spectra, corresponding to a well defined number of initially captured electrons. The set-up of the ion and electron spectrometer is described. Trajectory calculations for the determination of detection efficiencies are presented. The partial spectra are discussed in terms of the 'extended classical barrier' model.