Interior Temp Problems--Any Sugestions??

I bought my 840 ci 6 months ago
One owner, very low mileage (75000) and in very good nick
I bought the car in and live in London
I am having trouble though with the temperature inside the car
In summer , even with the air con on its getting very hot, espacially round the consul and, specifically at the back of the radio
In winter the windows keep steaming up and if the Air con is switched off you can still smell hot water from somewhere

I am rather loathed to take it in to let them trouble shoot the problem because, who knows what else will go wrong

I would appreciate any feedback, if any

Cheers
Chootspah