Bought a cheap one phone holder for about 2 bucks.

But the suction cup did not want to hold tightly at any plastic surfaces.
Googled this issue and discovered that i am not the one with the problem. Guys boiling the suction cups in the sodium, oiling them with whatever...
Here is my practical experience.
1. Applied the dry suction cup. Did not hold at all.
2. Slavered and applied. Held abot 5-10 mins.
3. Oiled with silicone lubricant. Held about a day.
4. Oiled with brake fluid (founded it under the hood

) and it still holds tightly during the week!!!
Hope I will be happy enough not to use last "heavy arms" argument - oiling it with garlic
And did you guys have such experience and what was the remedy?