After 2000 miles on my 50 cc E-ton, I have moved up to a 2004 Atlantic 500. The model I purchased does not have a topcase and I am thinking of adding one. The Aprilia product for this model is quite pricey. Does anyone have thoughts/experience with other brands and their mountings (not just ease of mounting, but also the structural soundness of same)? There is no mounting plate at present; a passenger backrest currently exists in that spot.
I appreciate the assistance anyone can provide.

As an aside, I completed the Basic Rider motorcycle safety course about one year ago and ride with a full face helmet, armored jacket, and gloves.

David