Generally speaking you can only challenge an MoT on the grounds that it has failed when you think it should have passed, and vice versa. Although the MoT testing guidelines are strictly laid down there will always be room for interpretation between tests, testers and locations. Conceivably you could have the car retested on another day or elsewhere and it would not receive an advisory.

If you are not challenging the pass or fail nature of the MoT then it is at the discretion of the location as to whether they will demonstrate the issue to you. While a completely clean MoT certificate is preferable, you have to decide whether the cost of repairing the wheel and another MoT is worth any potential loss in value when selling a car with a single advisory.