Hmmm, why woul not attending Open Days hinder your chances in getting a vac scheme? They are not mandatory and there is certainly nowhere to put them in your application. Therefore, firms won't know that you have not attended any and this would not reflect badly in you demonstrating whether you have an interest in commercial firms. Equally if you've been to 20, listing them would not show HR that you do have an interest in commercial firms.
If you've researched well that particular firm you're applying to, it would show regardless of open days. That's just another source of information.
But generally if you can formulate good answers to the app questions, have strong grades, speak another language and good extra-currics etc. then all things are pretty much in your favour.
Last edited by h-g-1; 30-07-2012 at 12:29.