Pretty much yes..like a double ended spray with a few differences. You need to look at the car concerned to see how much room you have to play with e.g. width, depth etc and the angle of the rear screen when it comes to the height of your flowers. Ideally you could do a mock up template with a block of foam on a tray and just use old flower stems to mark out the limits in each direction. That is, you would place the block in the centre and then cut the stems and piush them into the foam leaving the ends at the same position you will want your longest flowers or at least to tell you how far you can go. Think about the lowest flowers as these may not be seen if the seats are high, as opposed to flowers on a coffin where you would see them laying on the surface. You will probably see all the flowers through the rear screen though. If it is a hot day you will also have a greenhouse effect on the flowers and they will cook very quickly, so tender flowers are out. If it's a really posh car you will need to underlay with cello and an absorbent material or you may not be too popular.
You shouldn't need to worry about the driver's rear view as he should be able to cope with side mirrors.

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