They are called Caplugs and are widely available at a small fraction of $20.00.
I like how the e-bay site says it fits Smart Cars from 1989 to 2009. Also "Patent Pending" on a long existing product.
Beware of people who have one post who are essentially advertising their e-bay product for free on Benzworld.org. Check out that the name of the poster near matches the e-bay sellers contact info.
I have two friends who have recently purchased Smart Cars.
Haha, good catch. What some people do, and may make more sense is to buy standard size chrome lug bolts like used on MB's. For one, they look good in chrome and no caps to lose, for two, they are a standard 17mm head size for which you can buy a lug wrench for. I've have never seen any 15mm lug wrenches anywhere. Sure you can make one by getting a lug wrench like my Mr Lugnut with a 1/2 square head and then buy a 15mm thin wall deep socket for it but it's nice if you can use the lugwrench off your MB if you need it. You can buy the chrome lug bolts at discount wheel shops for about $2 to $3 each and you only need 12.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Caplugs 
Linear Mode
