I can't imagine a sub £1K 3-series Convertible being at all good.
205 CTi or CJ, Talbot Samba Convertible, Mk 1 Golf Clipper/GTI/CLI convertible (best, IMO), the aforementioned 19 (elegant, but a bit crap), are the first 306 Cabriolets that cheap yet, they're on a par with the 19 age-wise... Punto Cabriolet if you can find one, Astra Convertible (the Mk 3 Astra Convertible is actually quite nice looking compared to the hatchback)...
Cavalier Convertible (if you can find one)...
Rover Metro Convertible (see above) (K-series powered. Fun little things).
Mk1 Golf - that's a good one I hadnt thought of. She likes the 306s - we looked at a few of them when we got the MX5, probably a bit too pricey still though. Will suggest the Astra too - can you get them with a digi-dash, because I reckon that would be a good plus point.
She wants the convertable for the summer though, as she wont be doing that many miles and misses the open top-ness of the MX5. In september she starts a new job that requires a 50 mile round trip a day, so will probably be looking into something a bit more sensible then.
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