To all those out there that have been experiencing problems with items being stuck in your family inventory, I believe i have found a solution to resolve the issue.

I had 2 mercedes and 1 range rover stuck in my inventory whilst performing jobs as an architectual designer. Now i'm not sure if this will apply to all items but it worked for me.

As far as I am concerned it is as simple as sending your sims on holiday and when they return, the items should be available to remove.

I did do one thing whilst my sim was on holiday and that was trying to enable the 'alwaysallowbuildbuy' cheat but I don't think that will help but needed to mention it in case.

Apologese in advance if i have posted this in the wrong forum but after searching this problem and noting how common it was I felt it neccessary to post my experience.