Well it's made from camping mat foam , not sure where the crack is ?It looks sufficiently fragile to have gained that large crack.
Just below the left headlight and again halfway back from the headlight to the scuttle but on second look they're probably cuts to allow for a join for shaping though does give the impression of cracking that's been repaired.
Signs of use are good though , shows it has a life and carries it's scars well.It seems to mark fairly easily judging by the numerous marks. It's ingenious enough and the shape is pleasing but aesthetically the finish doesn't float my boat.