Are these common problems?

[LeMan]

Hi guys, new to these threads...but not to car forums.
Have recently picked up an 06 3.0d MSport X3 and are loving it!
However, have got a few niggles which i want to sure with the wider brain, to see if they are common problems or warranty applicable.

I've got some blistering on the chrome kidney grills?
I've noticed some corrosion in the small grooves, but now some much bigger blisters have appeared too.

I've also got some strange cracking on my headlights - an area of lots of hairline cracks about 2"x1". It almost looks like a small spiderweb or a small patch of frost. It's on both headlights (driver and passenger side) in exactly the same place (infront of the dipped beam bulb) The rest of the headlight glass/plastic and front of the car is perfect (apart from the odd stonechip)
Could it have been caused by the washer jets perhaps, on a icy cold morning!?! Again, just looking to see if it would be a warranty thing, or if anyone has come across it before.

Apart from that my rear sensors have decided to stop working... that i know will be covered

Any help is much appreciated... (picts attached - if i can work out how)