sorry probably a stupid question, but am looking at getting some smart tabs, have a 18ft mariah, with volvo 4.3, now from reading post i guess i'll need the 12 x 9 with what ever actuators, 60 i guess, but here's the stupid bit, are they 12 inches wide or 9 inches wide??????, i'm a bit squeezed for space, the speedo thing may get in the way????? <br />thanks<br /><br />simon