Check you log book when it comes as it may show 6 seats instead of 5 then you get to have fun with DVLA
Other than actually needing to carry 6 people, why would you want a double up front? They're so uncomfortable! No lumbar support, can't even recline the thing!
Although mine came from the factory with 5 seats but my V5 says 6...
It may affect your insurance? It could be argued that it is modified in the seating arrangement from what the factory/log book says. I got the dealer to send a letter in to DVLA on mine as it was meant to come with 6 and has 5. Log book said 6. Waiting for the new one to come