There's another very roundabout way of accomplishing what you want, if I understand your problem correctly (You need to fit approx. 4484 MB onto a DVD+R).
You are right that you can't overburn just a single MB with your BenQ 1650, so one way of accomplishing what you want is to overburn more than the minimum which I don't remember exatly now, but it's around 9-10MB.
If you use UltraISO ($40 shareware) to create an ISO image, and then add a dummy file (or files) of the appropriate size, you can then use the "advanced hidden" property on those files in UltraISO, and the files will use space in the image and on the disc, but they cannot be seen anywhere.
And this makes it possible for you to overburn the DVD+R with the desired file(s) on it and with no other visible files.
Buying a new high-quality DVD-R would be an easier solution.