Orientation of parts - Be sure to check and re-check orientation of blue/blue, blue/gray and gray/gray connectors. If a rod should hook into a double connector and there is no connection spot available to easily connect to, it may mean that the double connector is not oriented correctly.
Track pieces - Connectors should attach to the track pieces with a firm “snap”. If your track pieces keep popping off after you have attachedthem to the main structure, it is likely you have not "snapped" the connectors onto the correct side of the track.
Bend track pieces back and forth before adding to structure. Carefully examine instructions on places where the track needs to bend in a certain directions.
Connections should not be forced. If a track piece doesn’t seem to have an attachment spot on the structure or if the track needs to be forced to attach, it is likely that a piece or two were forgotten or are not in the proper position.
Specific Tips for Model:
Page 20, Step 26: The purple (ladder shaped) connector shown as already in place on the structure in steps 26, 28, 30, 32, 34 and 36 is actually not added to the model until Step 38 on page 26. The purple connector snaps directly on the track in Step 37 and put in place in the structure on Step 38.
Page 34, Step 56: Be sure to “snap” the Slingshot Launcher in place over the track.
Launching the Car
Be sure to hold the base of the track firmly with one hand while launching the car with the Slingshot Launcher.