I suggest a careful inspection may reveal a maker's name on the connector.  Feed that name into Google, perhaps in the form "xxxxx automotive connectors".  This may give you sufficient info with which to determine a part number.  Searching with this number may reveal a supplier.  Common problem is that minimum supply quantity is perhaps a 1000.  Ebay is a possible source for smaller quantities.
Alternatively it may be possible to obtain part of a recovered harness from a vehicle breaker, and splice in recovered terminals with wires attached.