I'm clueless as to why the OP's coverage would be higher on the smart. When I signed up with Progressive on the phone, the CSR I spoke with gave the impression they were aware of the smart's safety advantages and lower cost collision repairs.
I'm paying 2X256.29 = 512.58/year at Progressive. My deductible is $500.
I have the Diamond Membership, which just means I've been insured by them for four years. It's a loyalty discount thing. Plus I'm old and have a perfect record for more than 10 years. All of that counts, as well as your credit rating.
I'm thinking of giving Progressive's "Snapshot" program a try for a further discount. Only drawback is it connects to the OBDII port and I won't be able to use SGII for the test period. I think the evaluation period is 30 days, and they claim "up to" a 30% discount based on your driving habits: time of day and driving style.
20111003 UPDATE: Today I received the Snapshot device, and my six month premium bill. My policy cost has been reduced by $8.10 per year. Hey, every little bit helps.