I bought a pack of 5 of these...
http://www.ebay.co.uk/itm/111001025172? ... 1497.l2649
they come with a few different fitting options

Rear door/boot door light with the cover off

Springy bit fits different sized festoon bulb holders

I actually ended up taking it back out and tucking the black connector bit underneath the sprung bit first before replacing it all
It is a real tight fit, I had to cut back a bit of the self adhesive pad to get it in ok

all fitted in in nice and snug

The AFT has a shorter bulb but the spring fits fine

You could probably fit a larger one in the AFT if needed but I think it does just fine

If anything they may be a bit too bright when you are slipping out for a pee in the early hours of the morning but they are good for times when you aren't sleeping in the back.

**Edited** bit of a photobucket error