Brighton & Hove Wright Streetdeck SN64 CTU - Newhaven - 16.3.2015

Brighton & Hove Buses' fleet list shows this as being 'on loan' - presumably from the manufacturers. It didn't sound too healthy, as it was being driven around Newhaven, with rather a rough growl coming out of the back. If this is the only example in the B&H fleet, then I have seen it a couple of times in service in Seaford in the last month or two.
I think I saw that this model was going to be introduced to the no.12 route - Brighton to Eastbourne along the A259 coast road, via Newhaven & Seaford. The route has a couple of variants, 12A and 12X, and the closely associated Beachy Head route 13X.