Deffo look longer fella. Just picked my first Mauritus Blue 3.0 Z4 up two weeks ago on 47k. Got lots of lovely xtra toys such a xenons, M sport seats & wheel, CD multichanger. Just was after the Elipsoid 107's and got stuck with the 108's... so glad I got the 108's now.
Choice you have to make is do you want a facelift of go for a late 2005 and be in a position to negotiate harder... is 1st registered Aug 2005, 1 previous owners so am the third and yowza, what a lovely sound @ 3k rpm from that straight six. Gent had a compelling event to sell - his girlie had a son - hence needed a 4 seater... left him gutted, well beaten down on price but £8.75k richer.
3.0's are often overlooked especially they way fuel is at the mo, but did 38mpg on the way home @ 80 & is currently averaging 33 which am gobsmaked as you just can't help engaging warp speed every so often.
I run a new black edition A3 Quattro, but you're one amongst the masses. as the curves & lines on a Z4 are truly unique.
Good hunting fella... and remember the killer line when you first open negotiations 'It's a really beautify motor, well looked after, but what's the absolute lowest you'd take for cash'
PS: Have a look at my post on tyre prices, theyre a bit steep on this type of car but well worth the investment