GO:0035789

The orderly movement of undifferentiated metanephric mesenchymal cells (precursors to metanephric mesangial cells) from the mesenchyme into the cleft of the developing glomerulus, during development of the metanephros. [GOC:bf, GOC:mtg_kidney_jan10, GOC:yaf, PMID:10734101, PMID:19019919]