I have recently learned that 3M recommends using 3M Performance Finish car wax as a protectant on Ventureshield film. Performance Finish is a silicone-based LSP. Previously, Ventureshield was recommending Plexus plastic spray, but there have been some cases of yellowing with Plexus. I am now switching to Performance Finish. It will be the only silicone-based product in my inventory or on my car. Thought you'd like to know.
I understand that it's possible to put nearly anything on Ventureshield, but 3M recommends only one product at this time - I know it's theirs, but I have never known 3M to wrongly recommend a product for marketing reasons that underperforms. The Performance Finish is under $12 per 16oz. bottle, so it's not a bank-breaker. My Ventureshield installer says he has seen many applications start to turn brown due to the wrong LSP being used. It's more apparent on lighter color cars.