The Profile 300 & 500 and the G3 are completely different products.
The Profile 300 and 500 are compounding systems designed for the marine maintenance (fibreglass) industry.
This is from the Farecla website:
"Profile 300 is a mid range, high gloss, water-based compound capable of removing P1000-P1200 dry abrasive marks
Profile 500 is a light cut, water-based compound used primarily as a second finishing step to remove swirl marks and give a high gloss finish."
The G3 is a range of consumer products designed to remove light scratching from car paintwork.
Whilst the G3 will probably do the job, it is an abrasive like any other, you will get better results with the Profile 300 and 500 abrasives which are designed for polishing plastics.
You can get them online from East Coast Fibreglass
Edit: Brian will be along in a minute to tell you I am wrong and you should use toothpaste. :wink: