Anyway picked up a Black E53 3.0i 03 plate, I love it such a dream to drive - feel like a boss lol

A few things I would like to ask, I have searched on here and other places but cant seem to find definitive answers. Any help would be greatly received.
After about a week of driving I have got the message "self level susp inact" appear. From looking online it is an issue with suspension, the ride feels the same so bit unsure as to why this has shown up. What can I do ?
Every morning I hear air coming out the rear tyre for some reason, tyre is not flat or has a punchture. Has anyone had this before, any ideas as to what it could be ?
I want to upgrade interior lights to white LED's, I want it all changed. Can someone confirm the exact number of bulbs, as when I go on Ebay I am seeing LED interior packs but with a different set of numbers ?
Sorry to go on, I want to change the side repeaters to smoked LEDs like this -

I can only find these from the USA, http://www.ebay.co.uk/itm/BMW-X5-E53-LED-SMOKED-SIDE-REPEATERS-MARKERS-LIGHT-DARK-/300476708305?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Car+Make%3ABMW%7CModel%3AX5%7CPlat_Gen%3AE53&hash=item45f5ceb5d1
Does anyone know a source in the UK to get them and is there a guide/video ti fit them. I would imagine they just pop out and replace, but dont wanna start messing up the car
I am based in North London, so if anyone knows of any good fitters for ICE, tints, wheels etc please let me know.