For the 1999 Buick Regal, the supplied fitment data lists a 9005 bulb for the high-beam headlight. No low-beam bulb is listed in this fitment data, so verify the original bulb before ordering a replacement. The fog lights use 893 bulbs.
At the front, the turn signals and parking lights use 4157NA, while the front side markers use 194NA. Rear lighting includes 3057 turn-signal bulbs, 3057R brake bulbs, and 1156 reverse bulbs. The center stop light uses 1141, and the cornering lights use 3156.
License-plate and tail-light fitment includes multiple listed options: 194 and 7441 for the license plate, plus 194, 7441, and 3057R in the tail-light listing. Compare the original bulb for courtesy lights, which have several option-specific choices.