The car(member) voting and the car voted for can't both be del rods members. In plane English, a member cannot vote for a club member.
There can't be duplicate votes, but the original vote and all other votes count.
This code should work.
Code:
If Me.V5 = Me.V1 Or Me.V5 = Me.V2 Or Me.V5 = Me.V3 Or Me.V5 = Me.V4 Then
Me.V5 = 0
ElseIf Me.V4 = Me.V3 Or Me.V4 = Me.V2 Or Me.V4 = Me.V1 Then
Me.V4 = 0
ElseIf Me.V3 = Me.V2 Or Me.V3 = Me.V1 Then
Me.V3 = 0
ElseIf Me.V2 = Me.V1 Then
Me.V2 = 0
End