I just purchased a pre owned 2004 ML500, two things, how do you tell if it 163 or 164? Also I want to add Class III hitch, MB dealer says MB no longer has parts.

 

2006 was the first model year of the 164..at least here in the U.S.

 

You have a W163.
Last model year for W163 was 2005.

For the MB hitch, you may have to try some online OEM parts sites,
or eBay. Check the MBWorld Classifieds every so often too. You never know what will show up.

Carlos

Saprissa@aol.com