I like to shoot hot rods and classics and my kit with the K-3 usually consists of:
- Sigma 17-70/2.8-4.0 (C)
- FA 35/2.0 or Tamron 24/2.8 (01BB)
- Rokinon 8/3.5 or Zenitar 16/2.8 Fisheye
The zoom because it's versatile, the fisheye for creative potential, the 35mm because of its size and near-normal perspective, the 24mm because of it is good for "street" work. Be sure you have something capable of close focus for trim details.
In regards to your 18-55...One of my favs, taken with the 18-55/3.5-5.6 kit lens on the K10D at a local concours d'elegance...
1954 Jaguar XK-120 drophead coupe
Steve
(...I vote the 18-55 plus 10-24...both will get a work-out...)