Love what you're doing with the headlamps.
GM decided that 1980 would be a '1-year' model across the range of G-Body saloons, the Cutlass, Monte Carlo, Regal and Grand Prix all went from single lamps (only a 2-year run in itself, 78/79) to twin lamps for 80 only. Then in '81 they revised the entire line-up completely to the newer body styles.
The single rectangular lamp look you've gone for echoes the 1-year only also 1988 'Euro' front end for the Cutlass.
GM decided that 1980 would be a '1-year' model across the range of G-Body saloons, the Cutlass, Monte Carlo, Regal and Grand Prix all went from single lamps (only a 2-year run in itself, 78/79) to twin lamps for 80 only. Then in '81 they revised the entire line-up completely to the newer body styles.
The single rectangular lamp look you've gone for echoes the 1-year only also 1988 'Euro' front end for the Cutlass.