The list says Park Avenue 3.8 is limited to 99-05. But this 1998 reads fine, and prompts for a license - I haven't tried going farther than that (not sure I'm even keeping the car at this point, plus there's not a whole lot you can do with a P04).

1998 Park Avenue L36 1G4CW52K7W4656345.hpt

What would it do different if it was really not supported?