The best way is to look at the plugs on your 2005. If the connector plugs on back of your radio are black in color they are "World plugs" 16 pin and 20 pin (plus an additional 8 pin connector if it has the sub woofer option). The newer Ford type radio connectors (most 2007 up) are gray in color called "Phase 2" and are 24 pin and 16 pin (plus also an 8 pin connector for sub woofer option). What ever radio you get be match your connectors be sure to match the number of connectors (2 plugs to 2 plugs or 3 plugs to 3 plugs) to avoid an mismatch of sub woofer output. The radios might have an different way of mounting to the dash (spring clips on side versus metal mounting tabs) also which might be another consideration. If they mount differently they can be made to fit but not without modification.
You can convert your "world plugs" to "phase 2 plugs" but it requires special rewiring to get it done.
