Hi folks, This Christmas I bought my son (5yo, who is pretty short on patience) the Cops and Robbers Quickbuild (https://www.scalextric.com/sets/standard/scalextric-quick-build-cops-n-robbers-set.html). I have not touched a set in over 20 years, and this is his first, so it's important we got it right. In short, it's been nothing but a massive headache. The cars barely run a few laps around the figure 8 before they'll lose connection, stop and stutter, do a 180 spin and stop. Typically, a session will look something like: 1) Start them up, they'll run half a lap, then come to a halt; 2) Give it a bit of a push... it'll go another half lap (hopefully)... and stop again; 3) Run a few more laps, stuttery and twitchy, stop again. Push it... go again... 4) Rinse and repeat. To note, the "police car" has an audible siren. It's a clear sign of what's occuring when the siren noise will stutter and go off / on constantly. Also note the track is on a flat, hardwood floor. Good power connection. I've tested small details such as holding the car against the track, lifting the rear wheels and watch it run... which has no problem. We've taken them to the shop (who are honestly a really patient, accomodating group here in NSW - SlotShop in Marrickville - free plug!) who have rejigged the contacts and internals of both cars. Though the problem continues. They described these tracks are 'bouncy' and 'soft', and how to further tweak the wiring to inprove the contact (ie: "spread" the contact wires outwards, and push them away from the car to improve contact), though this has made little improvement. However, for this amount of effort that's being taken... for something that should "Just Work", both my 5yo son and I are losing patience. I don't want to request a full refund, though I feel it's getting to that point. Is this simply how Scaletrix are? Is it simply assumed there'll be a stuttery nature to them, or should they simply go round and round and have minimal issues? If needed I can link a video on here to what's happening, if that will help.