Hi there,
I work for Autoglym so can answer this with some confidence
Bumper Care, Bumper & Trim Gel and Plastic Conditioner are all the same product. Bumper Care was the old name for Bumper & Trim Gel but the product remains the same, and Plastic Conditioner is the name for the same product in the trade range.
I'm not sure where the 'leave for 3 days' advice came from, but you only need to apply it with a soft cloth or piece of sponge to the trim and then buff of any excess. markyzs180 is right, do not overapply or you will get runs when it rains, but these can just be removed with a cloth and a squirt of quick detailer.
For future reference instructions are here:
Instructions. Shake well. For best results, heavily soiled surfaces should be pre-cleaned with Autoglym Bodywork Shampoo Conditioner or Autoglym Car Interior Shampoo and dried.
Apply with a small piece of sponge or a clean, lint-free, soft cloth. Rub firmly to ensure an even coating. To treat complex grilles, apply sparingly using a small paintbrush. Bumper and Trim Gel will not harm paintwork and may be polished off using an Autoglym Hi-Tech Finishing Cloth or soft cotton cloth.
Use Bumper and Trim Gel on all exterior plastics, vinyl and rubber, including; moulded plastic bumpers, grilles, mirror cases, mouldings, wheel arch trims, door handles, vinyl roofs, rubber bumpers, tyre walls, spoilers, mud flaps and matt black trim panels. Avoid contact with glass.