▁The ▁first ▁generation ▁En vi ro 2 0 0 , ▁then ▁known ▁as ▁the ▁Trans Bus ▁En vi ro 2 0 0 , ▁was ▁un ve iled ▁at ▁Co ach ▁& ▁Bus ▁ 2 0 0 3 ▁by ▁the ▁vehicle ' s ▁then - man ufact urer , ▁Trans Bus ▁International . ▁Two ▁dies el ▁trial ▁bus es ▁were ▁initially ▁produced ▁for ▁display ▁in ▁ 2 0 0 3 . ▁ ▁The ▁first ▁generation ▁En vi ro 2 0 0 ▁was ▁unique ▁in ▁that ▁it ▁had ▁a ▁door ▁both ▁at ▁the ▁front ▁and ▁at ▁the ▁rear ▁of ▁the ▁bus , ▁as ▁such ▁a ▁layout ▁is ▁rare ▁in ▁the ▁UK ▁- ▁most ▁dual - door ▁bus es ▁in ▁the ▁UK ▁have ▁a ▁door ▁at ▁the ▁front ▁and ▁another ▁door ▁around ▁the ▁centre ▁of ▁the ▁bus . ▁This ▁door ▁layout ▁was ▁achieved ▁by ▁placing ▁the ▁engine ▁vert ically ▁at ▁the ▁rear ▁off side ▁together ▁with ▁other ▁dri vel ine ▁components , ▁which ▁also ▁created ▁a ▁full ▁low ▁floor ▁layout , ▁common ▁on ▁bus es ▁in ▁Cont inental ▁Europe . ▁The ▁vehicle ▁also ▁incorpor ated ▁an ▁" En vi ro ▁Pack ", ▁intended ▁to ▁vent ▁exhaust ▁em issions , ▁noise ▁and ▁heat ▁away ▁from ▁ground ▁level ▁and ▁thus ▁al ight ing ▁passengers . ▁ ▁The ▁innov ative ▁design ▁meant ▁that ▁the ▁En vi ro 2 0 0 ▁could ▁hold ▁up ▁to ▁ 2 5 % ▁more ▁passengers ▁than ▁a ▁vehicle ▁of ▁equivalent ▁dimensions ▁( 1 0 . 4 m ▁long , ▁ 2 . 4 m