Thanks Mmikey.
The LEDs were ordered from partsulike.co.uk. They do a kit for the interior at £19.99 but the 501s are only available as CANBUS bulbs in white or blue. The red 501s are non-CANBUS but they still work. They also sell other colours too.
Depending on what model Leon you have(if it's a LEON) the interior kit might not be what you want. The kit has 5 FESTOON bulbs and 2 501s. My MY2011 has 4 FESTOONS and 3 501s.
If you sign up and e-mail Dave, he will sell you the kit with your configuration as one of the options above for the same price if it's white or blue.
If you want a colour other than white or blue you will need to order the FESTOONS you need seperately from the coloured 501s.
The only issue with the 501s i have found is that if the rear light switch is not set to the central position, the front centre lights will glow very dimly but not enough to distract you. There are no light warnings on the dashboard either.
If you quote code PROMO:10 you'll get a 10% discount as well.
Fitting was really easy.
If you use a very thin screwdriver and prise down the 2 front edges of the front light it will slide out easily. The rear is easy as well if you prise out the edge closest to the centre first. The 2 sunvisor ones have a small cutout on their edge nearest the door that a screwdriver will fit in to. This will allow you to lever them down quite easily.
If you need any pics i'll gladly oblige.