And i've got mine in a Polo '00/'01, just below the center vents. It can get quite warm with the heater turned up, ~50C, and I've triggered the temperature alarm in hijack once - set at 55C. Doesn't really seem to bother the unit though. The Polo has been lowered 40mm and sits on 45-profile tires, so it's quite stiff - never had a problem with the MkIIa (the MkI connector would sometimes, specially if a little dirty, not give perfect contact [ie bounce and scratch] when going over potholes and railway crossings)

/Michael