18'' Wheels on your A? What size tires are you running? Post Pics!

4.5" = 114.3mm. Exactly. That is the conversion, no rounding, feel free to try it yourself.

1"=25.4 mm. 4.5 x 25.4 = 114.3

Any wheel advertised as 5x114.3 will fit the bolt pattern for LBP mopars.

5x115mm will not unless you open up the bolt holes, I wouldn't do it myself, but I'm sure its been done.

5x4" is not the same as 5x100mm, which is what neon wheels are.

4" = 101.6mm.

I wouldn't try to hog out the bolt holes on a set of 5x100's to fit on SBP mopar. But again, that's just me, I wouldn't be surprised if its been done.