Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Lots of plastic, Bike fell over on roof.

I hated these trays from the first day I got them. I had Thule's predecessor to these and they worked just fine. Bikes never felt secure in this tray. (Note: this is not ignorance or user error... I worked as a mechanic at multiple bike shops when I was in college and do all of my own and friends' wrenching.) My hunch was confirmed one day when I turned into a parking lot with a big bump at the entrance and the bike (fairly heavy touring bike commuter) fell over on top of the car. Luckily it fell toward the inside and just rested on the roof, and the rear wheel was still strapped in. Needless to say, that was the last straw.I had been reading about the Rocky Mounts Pitchfork trays and bought two of them. They're all aluminum and steel, much sleeker, lock the bike down incredibly solidly, cheaper, available in a million colors, etc. I couldn't be happier.Stay away from the Thule 517. It's an overpriced and unreliable.