Instruct: Classify the given Amazon review as either positive or negative.
Query: very dissappointed.

My son got this for Christmas. What excitement!! We opened it, put it together and the cars immediately flew off the track as they rounded the first curve. Adult concentration could ALMOST get the car around the loop the loop without falling. After a couple of races, the cars stopped working reliably. The cars have a wire braid underneath which gives them their power. The braid either moved or fell out and didn't stay on the metal of the track, (even after countless attempts at adjusting it) thus the cars now don't work at all. Do not buy this. We are throwing ours out. SUPER dissappointed.