So, I bought the Nikkor AF-S DX 35mm F1.8G lens last March from Amazon 'cos they had a great deal - $189. But it never work quite right with my D7100 in autofocus mode - always a bit soft under every possible setting. Always had to tweak manually whenever I use the AF setting. So finally I decided to send it back to get fixed under warranty (1 year warranty.)
Used the Web support, entered all info, printing out all the mailing slips etc. But they required the warranty slip and the invoice which I don't have. Just printed the Amazon payment confirmation and sent with it. So, now I wait and see how well Nikon Repair can take care of this!
Will keep you all informed!
<Grumble.. grumble.. hate to have to send thing back after purchase!>