As I stated, Raggtopp cleaner/conditioner is the way to go for care.
Do not use synthetic brushes!!!! Use horsehair, boars hair etc that is stiff, but not too stiff that it will mark up the fabric.
Always test areas not normally viewable to make sure all tools and products will not damage the fabric.
Plastic can make it that much more of a challenge. Wash it often to keep it clean, do not use any brush on the plastics. Clean with Plexus when you first see any problems.
Most Porsche Cab owners use Raggtopp and this is exactly what I use and suggest for owners after doing one. I will show them how to wash and care for it, which will last the life of the car as long as stains do not get imbedded into the fabrics.
Since this is a new Vette, take a picture of the top now dry and another when you have wetted it down. Keep these in your detail kit and look at them to compare if the beading is becoming larger, or not at all. Also, look at the depth of color for sun weathering. After treatment, I use 303 just to add a bit more UV protection.
As long as you record the time it looks now, you'll have a better chance in keeping it looking brand new.
Regards,
Deanski