Yeah, but I think that centre bore is actually 54.1? still, mine are the 15" wheel with the 45 offset. I can get a picture of the centre hub with it all fitted if you like, but either way, the actual ‘lock’ nuts are smaller than the original nuts on the car! so they would fit in any wheel that the original nut is used with.
Ive got my eye on a set of BBS just now, fitment is listed (vaguely) as ‘VW, BMW, Vauxhall’. 4x100, 14 inch, 6.5J, ET35 offset and 57.1 centre bore. These should fit a mk1 unless Im mistaken (with correct nuts)?
The BMW fitment BBS are indeed larger centre-bore than the mazda. you’ll need spigot rings to make the fitment to the hub correct. I think there’s quite a few threads on here and mx5nutz about fitting those wheels. The offset is also at the furthest out that would work happily, the nominal for the mx5 is 45, but up to 35 will fill out the arches. Some have fitted lower numbers offset, but it’s going to be at the end of what’s possible before scrub radius is affected and possible rubbing of other components, mostly wings.
http://www.mx5nutz.com/forum/index.php?showtopic=914&st=20
deliberately linked page 2 because they realised their quoted list of multiple manufacturer’s wheels had an error quoting 64.1, not 54.1mm for MX5.
halfway down this page one guy quotes an external link to a supplier of rings to reduce the centre bore to the right one, and they are discussing the VW / BMW fitment BBS’s
HTH.