UEFA qualifiers as guests along with Canada and Mexico since UEFA doesn't have the same amount of teams in each group. USA, Canada and Mexico would each have a base location in Europe for their home matches (USA in England, Mexico in Spain, Canada in France?) that way they don't make the regular UEFA teams travel outside of their normal area. The games would count for the UEFA teams and would give USA, Canada and Mexico competitive games before the World Cup.

This would never happen but it's what I would like to see.