just a quick update.
I went to Home Depot on the weekend and called up some local auto parts supplier (Lordco and Napa) They all told me 3M tape is the way to install it. Silicone glue is for different application purposes, designed to seal gaps and watertight certain areas which is totally unrelated to cars. If caulking is the correct adhesive for car applications, then Lordco and Napa would've stocked a whole range of silicone glue, but that is not the case.
basically, If 3M tape cannot hold the part down, Its clearly a fitment issue because 3M tape can withstand weight and pressure of up to 5 pounds.
If they tell me to use silicone caulking to buckle the sides and fill the seams in the front, they might as well tell me to use a staple gun to nail it down. this is just complete nonsense.
Can any one tell me why I should choose silicone caulking over double-sided tape? the more input the better!
I've read so many stories on vendors blatantly denying refunds and ignoring their clients. Now i know how it feels like to be bullied by them.