Rover owners: tf washer bottle adapter

Is this possible? I have always wanted to raise the windscreen washer bottle opening above my spare wheel so I do not soak everything when topping up with screen wash. Some cars and vans have washer bottles with separate spouts. I might try a rover 200 pre 2000my neck/spout. I am finding it difficult to find dimensions to work out if this will work. What have other people done? I don't just want a funnel.

Other possibilities: Renault megan flexi pipe, Nissan Almera top tube, scudo van, peugeot 306 pipe or citroen saxo vtr top tube.

Any ideas very welcome.