Aware of it occasionally in both our cars - Xantia and Berlingo. Each has a 60litre or so tank under the rear seat. I must have learned to live with it.

Agree with GB. If it's spoiling your enjoyment of the car adding some extra insulation is the way to go.

I have the 2010 si petrol but never heard the fuel sloshing as you mentioned,but theyve altered the design I think, looking at it,perhaps Honda took away some sound deadening in the tank area, I think its mid mount on civic

though Honda said they increased sound baffles on latest car?

As far as I'm aware for the 2006 Civic onwards, Honda followed the same design principles they used for the Jazz and postioned the fuel tank beneath the front seats - see http://www.honestjohn.co.uk/carbycar/honda/civic-2006/?section=cabin - to free up interior space.

Wasn't that where the WW2 Jeep had it's fuel tank - with often disastrous results.

I find the tonal quality of the indicator relay clicking decidedly distracting. I wonder if VOSA are aware of the problem...?

I think they now come as standard on the Special Equipment models.

I dont recall any car Ive had, before the Civic, where you cannot hear the fuel moving about the tank above half full,the Rover 25 being the worst for that IMO