Phone tablet heavy dock for car dash

Phone or tablet dock for table or car's dash. Dock has container to fill with sand or steel to make it heavy.
I've created it to use in my car and I don't like to hassle with windshield suck cup monts. I want just to easy drop and take out. Designed to use with phone case.

**V2** Updated version. A bit narrower and lower weight tray 80x80x8mm. I found nice 39x39x3.5cm washers and 8 pcs is enough for weight. Put a piece of double sided sticker between the washers to prevent clatting.