QUOTE(cnstars @ Aug 27 2004, 02:05 PM)
The bolt pattern for that year eclipse is 5 X 114.3 (metric) also 5 X 4.5 (standard)
If you bump them up to 20's most likely you'll have to cut out the wheel wells and or get some 25 series tires. The wide body kit will only effect the offset of the rim you'll have to get. That will have to be determined by how much the kit will stick out. A good motto that I always follow is " do go more than 3 sizes bigger than your factory rim size" ie. if you have 15's, max out at 18's / 16's max out 19's and so fourth.
the 3 size max is a good rule of thumb. if you want 20's, id definatly get the wide body kit, this will allow you to run a different offset and move the wheels out away from the struts. when the wheel tire combo gets too big, you start hitting suspension parts, but if you cvan move the wheel out, past the obstruction, then your golden. but, this will also cause abnormal wear on bearings and such due to an ofset thats incorrest for the geometry for the car. id stick with a 17, maybe 18 max. even with an 18, your looking at rubber bands for tires.