alloy wheels ?

[italianxrays]

I remember a nice set of Maserati alloys fitted to a 124 coupe owned by the same lad I acquired my old sport from, they looked the business........but, I generally get confused on suitability for 131's.
I know the PCD is 98 but that 100 can be fitted with wobbly bolts ? or adaptor plates etc.
These alloys I spotted on ebay & I just thought might scrub up nice for the 131, I was also looking at a set of Watanabe alloys as fitted to several classic Japanese cars, they are similar to the superlight in style but again PCD is 112.... I think ?
Can someone explain in laymans terms why this is so critical apart from safety aspect is it about possible fouling on suspension or calipers ?
Sorry if I appear to be a bit thick about this.
It appears there is also a niche market for a large alloy for the 131 Abarth replicas ? with a period style similar to original Cromodora.
Thanks for any advice on this subject.

http://cgi.ebay.co.uk/MASERATI-BITURBO-WHEELS-SET-OF-4-6-5-X14-98-PCD_W0QQitemZ280298752466QQcmdZViewItemQQptZUK_CarParts_Acc_Wheels_tyres_Rims_Car_Wheels_ET?hash=item280298752466&_trksid=p3286.c0.m14&_trkparms=72%3A1299%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

Like these I think :
http://forums.vwvortex.com/zerothread?id=3791833

Watanabe are like these :
http://cgi.ebay.com/ebaymotors/JDM-RS-Watanabe-RS-8-Speed-Star-Wheel-16-4X114-3-Rare_W0QQitemZ350147513870QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item350147513870&_trksid=p4506.c0.m245&_trkparms=72%3A543%7C65%3A12%7C39%3A1%7C240%3A1318

not this type ( Formula mesh ?) :
http://cgi.ebay.com/ebaymotors/B24-SSR-FORMULAR-MESH-14X10-AE86-510-240-WATANABE-TRD_W0QQitemZ310071974261QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?_trksid=p4506.m20.l1116

  Cheers anyway

[alan.acs]

pcd is pitch circle diameter . which is 98mm for fiat this means the wheel studs spacing or the distance the studs are apart.
 so wheels with a pcd/stud spacing of a ford 104mm wont go on, or your example of 112.mm
the ET is how far inset from the hub centre line the wheel is example ET 49 for fwd vauxhall? is with most of the wheel inset. ET 0 is no inset or offset.

The ET is what effects strut to wheel clearance.

 hope this helps.