We propouse the study of crystal-field or vibron excitations along the series RAgxCu1-xAl3 (R=Ce and La, 0<x<1), where we expect to studing two main aspects. The first one is related with electron-phonon interaction and so how the magnetoelastic coupling changes under the hybridization of Cu and Ag d-bands with 4f-electrons, specially, on those type of phonon modes existing in CeCuAl3. The second one is related with the origin of ground-state along the series, from a 3D-antiferromagnet for CeCuAl3 to a 2D-weakly ferromagnet just within the basal-plane for CeAgAl3. Kondo interacction will be studied from the analysis of the quasielastic linewidth.