Towbar Issues

[21stCentury]

Hello everyone, this is my first post.

I have recently ordered a new A4 B8 and assume that by now I'm guaranteed to get an MY2010 model.

Before ordering my car I contemplated the towbar option but at £650 I thought I could save myself the expense by fitting one myself (since towbar preparation appears to be included as standard now).

I have since read a number of posts appertaining to the fitting of towbars (issues with cooling, transmission, expensive retrofit of electronics etc.) and wonder if I have made the wrong decision. I have also read a couple of articles loosely implying that the problems only affected earlier models but nothing that definatively stated that there were no issues with later models.

I only intend to tow a single motorcycle trailer (not much more weight than a large passenger!).

Can anyone shed any further light on the matter? Are the issues resolved on models with towbar preparation included (i.e. MY2010)? Would towing a 90kg dirt-bike on a single trailer really cause cooling problems?

Thanks.