Since no one has addressed one of your primary concerns about removing too much gelcoat...in plain language...well, you can't.
For an 89 Regal, you will have a VERY difficult time removing too much gelcoat - read darn near impossible.
The edges are where you'll have your "best shot" at removing too much.
As one of the previous posters indicated, you can try an inexpensive can of white Turtle wax polishing compound and the correct cutting pad (that will also be white) and try an area to see if your cutting(removing) enough for your satisfaction.
The yellow pad is needed to attain a higher gloss and you would switch to a finer polish/sealer for the 2nd round - where you will still be (should be) removing some more material.
Just an fyi - the specific pad used has "cutting" characteristics and the pads need to be spurred often and rinsed when they are too loaded up.
While we use more expensive products, a small can of the white will only set you back ~$7.
For an 89 Regal, you will have a VERY difficult time removing too much gelcoat - read darn near impossible.
The edges are where you'll have your "best shot" at removing too much.
As one of the previous posters indicated, you can try an inexpensive can of white Turtle wax polishing compound and the correct cutting pad (that will also be white) and try an area to see if your cutting(removing) enough for your satisfaction.
The yellow pad is needed to attain a higher gloss and you would switch to a finer polish/sealer for the 2nd round - where you will still be (should be) removing some more material.
Just an fyi - the specific pad used has "cutting" characteristics and the pads need to be spurred often and rinsed when they are too loaded up.
While we use more expensive products, a small can of the white will only set you back ~$7.