Tail Lights - Upgrading From Pre-Facelift To Facelift Ones

I got a good deal on a set of facelift tail lights, so snapped them up thinking it would be a nice easy upgrade for my 2000 Octavia.

Just fitted them and discovered they are a bit longer than the pre-facelift ones, so the plastic panels that slide in under the lights no longer fit.

By the looks of it I'll need to get the facelift rear bumper with the newer plastic panels. However I don't want to go ahead and do that, to just discover there is something else that’s changed or that it is just the plastic panels I need.

So, can anyone tell me if I;

• Just need to get the shorter plastic panels
• Need the shorter panels and bumper
• Need so much stuff I should just go back to my old lights :P.

Cheers