We present fully differential cross-sections (FDCS) within the four-body formalism using the three-body Coulomb wave (4B-3C) for the single ionization of He by 3.6 Mev/amu AuQ+ ions. The purpose of this work is to investigate the validity of the 4B-3C model for more highly charged ions. By comparing our calculations with experimental data and the three-distorted-wave eikonal-initial-state (3DW-EIS) approximation, we find the 4B-3C predict unique forward peak structures in the FDCS and broadly reproduce the experimental data over the entire angular range in a satisfactory manner for Au24+. Clear discrepancies are found between both theories and with experiment for Au53+.