The coumaran-argon van der Waals (vdW) complex has been investigated using a combination of (1+1') REMPI and ZEKE spectroscopy, supported by ab initio molecular orbital calculations. Coumaran (2,3-dihydrobenzofuran) has a puckered, nonplanar equilibrium structure in the electronic ground state which allows for the formation of two energetically nonequivalent pi-bound geometrical conformations. The experimental observation of bands attributable to two isomers in the REMPI spectrum is consistent with a significant barrier to planarity existing in both S-0 and S-1 states. The two isomers are related through the ring-puckering motion but the interaction of the argon atom with the monomer results in an induced asymmetry in the potential which transforms the ring-puckering tunnelling motion in the isolated monomer to a localized vibration near nonequivalent local minima. Both REMPI and ZEKE spectra show rich vibrational structure, characteristic of excitation of the long axis van der Waals bending mode and the stretching mode, as well as combination bands involving the vdW modes with low-frequency out of plane intramolecular vibrations. The vibrational structure is consistent with a shift in the position of the argon atom along the long axis upon excitation and subsequent ionization, as well as a modest reduction in the van der Waals bond length.