It sounds like your boss'* car is almost a carbon copy of mine. The tanish-silver both cars have is Old'* "pewter".
I'd be surprised if more than 10% had the L67. I have only seen one , and that was on a used car lot in 2000. It was a black beauty, with about 25,000 miles. It was considered a "high mileage" car for a 1999, and was listed as $ 11,000.00
I should have snapped it up...but wasnt in the market for one in those days. I certainly wish mine was a L67.
1999 Buick Regal LS
ZZP 2.5" SS 304 DP, GTP Cat Back , GMPP Handling Kit, poly links and midpoints, HIR 9012/9011 with upgraded relay harness, 5000k HID fogs , 12" Impala/MC brake upgrade, Mag cat 94106, Ported and Polished LIM