My dealer did not even try to get me one that was in stock! then again ive gone for an FR edition so there probably arent any stock in the UK when i ordered.
You can de-gap with SEAT approved springs from a dealer... but they will bend you over a barrel and do terrible terrible things to you to pay for it ;-)
You could look at wrapping the roof section, though that tends to only really work with a bright colour car as an accent. You could invest in some 18" wheels to reduce wheelgap and look beastly (though it would be worth seeing is another MK5 on here has run them, as id be worried that they might catch in the wheel arch at full lock)
Bootliner is a must to keep it neat and shiny ;-)
dont overlook a bluetooth ODB2 adapter and a few quid for torque app on android. very handy gizmo.
You could always look at retrofitting a reversing camera, stick it high in the window tuck the wire in the cracks of the roof felt, run it down the beam, under the seat, and into a little monitor by the cup holders
