The manual for it actually says it is good for 7 years so yeah I wonder if that is a way of drawing attention to the fact?
I feel like extended warranties can be so gimmicky, if a company is really going to stand behind its product they should stand behind it, no matter what. You shouldn't have to buy it at one particular store where the price is higher to get more coverage. It's like $100 less on Amazon for the current version.
(Mamas and Papas is doing this in the US - they say on their website their products are only covered if you buy them at BRU. I feel like its another angle of price fixing and I don't like it at all)
eta - I will admit I buy things at LL Bean or REI, because of the life long warranty, but they give you that coverage whether you pay full price or sale price - it's more their way of saying "we sell quality." This doesn't seem like it's BBB standing behind the seat, it seems like it's Britax saying if you buy it there, we'll give you more coverage - so it's different IMO. This is listed on Britax's page as well as BBB, I could be wrong but I think it's a Britax promotion.
http://www.britaxusa.com/car-seats/advocate-70-cs/product-bundles
They don't list anyone else as doing it. But they do seem to have an XE version of all the new gen seats with a 7 year warranty at BBB... I dunno... seems fishy to me. It's like a new version of the BRU exclusive covers, such as wicker, which I paid extra for on a RA40 when DS1 was a baby, because it was so soft and looked so nice with his eyes...