If you want drive the i8 without a roof, get ready to pay for it. A new report from BMWBlog alleges that the i8 Roadster will cost nearly $20,000 more than the regular i8.

Starting at $163,300, the i8 Roadster introduces not just a drop top, but 20-inch wheels, a heads-up display, heated seats, and E-Copper leather.

And that's just the beginning. According to the report, laser lights will set you back more than $6,000, black brake calipers with ceramic controls another $2,500, and special colors (Crystal White Pearl Metallic, Frozen Grey, or Frozen Blue) will run you another $1,800.

And to go with all that special, the i8 will churn out an extra 12 hp, bringing the total but 369 (damn good time).

That extra power, though, will have to compete against added weight since losing the roof costs the i8 130 lbs in stiffening structures, bringing the total up to 3,500 lbs.

If you're tempted you can get your order in with BMW, with deliveries starting later this year.