Thought I'd share a recent addition to my Dahon Curve D3. I've been searching for a decent rack for my Curve. The Arclite Aluminum rear rack is a little too low to fit panniers, so I did not get it.
In the end, I got a Beto rack after my friend Ryan got his MU P24 fitted with a Beto baby seat that came with a rack (he also owns a lovely restored Dahon III Classic). The LBS uncle added metal strips to ensure his rack fit his P24, and I decided it would work on my Curve too. Since Beto sells the alloy rack separately, I got to buy it sans baby seat.
This is what it looks like:
Dahon Curve with Beto rack
Dahon Curve with Beto rack and Lotus front panniers
Dahon Curve folded, with Beto rack
The rack does not get in the way of the fold. I can fit front panniers on it, but rear full panniers are a little too long and can create heel strike. I've carried my Macbook on it, inside the panniers with no problems. And even mounted a Topeak MTX DXP trunk bag via the velcro strips on the rack, also no problems.
Handling is fine and I am now a happy camper.