Britax B Dual adapters -help!

[LaTristesse]

So I have a B Dual and bought some adapters on eBay so I could move the car seat in the top position forward a bit to give DS a bit more room in the bottom seat. All brilliant so far.l. When the adapters arrived there was also an extra bit in the box (2nd hand so could possibly be unrelated and a wild goose chase!), but I have no idea what to do with it!

There are 2 pieces, labelled left and right, little black plastic straight oval-shaped tubes, about 10cm long with a sort of grill in the back and a hole in the front where you can push a matching something in to extend whatever it is!

Any ideas?!

The tubes are to extend the hood up on 2011 and possibly 2012 models. People used to complain about the massive hood so Britax changed it so you can choose to have a normal sized hood or a huge one!

Oo ok thanks! DS loves hiding under the massive hood so I reckon we won't need them after all that?, thanks for clearing up the mystery!