The optical absorption spectrum of the Ti8C12, and V8C12 Met-Cars is calculated using time-dependent density functional theory within a real-space, real-time scheme. Other ground-state quantities are also calculated, such as the ionization potential and the electronic affinity. The broad absorption features of the calculated absorption spectrum are related to experimental results about delayed ionization and delayed ion emission phenomena that have been observed in these structures. (C) 2004 Elsevier B.V. All rights reserved.