85genius said:
Personally I would go for neither of them I just wouldn't pay £6500 for a 3.0i that's getting to 3.0si money albeit on a higher milage car...
I'd either go for a 3.0 with a few more miles on it for which you will find for 4.5k-5k if you look long enough or hold out for a deal on an si....
Dont let mileage be a major factor for you, my first Z4 was on over 120k when it got written off and was running sweet as, buy on condition and how it has been looked after lower mileage does not always a better car make....
Also forget the 2.5 they are awesome cars and my first zed was a 2.5 but I bought it without first test driving the bigger engine, when I bought the second Z4 I went for a 3.0si
Exactly this. In fact si roadsters have come down at the bottom end below this figure if you have a touch of patience. I paid £6600 for mine ( '07 3.0si with 75K on clock in mint condition) around 4 months ago. Mileage on these engines isnt really a deal breaker. worth baring in mind that the SI is facelifted, better looking, and more powerful than the ones you have suggested.
Found this one priced at £6900 which looks like a gem - 3.0si, saphire black, heated and electric M sport seats, new waterpump, inspection 2 done within last 10K, Full BMW Service History, Gaptech, and only 67K on the clock. With a cash offer of £6500 I am sure you would bag it from the seller without much hassle.
Needs only 2 things sorted - a ding in the front wing and the wheels refurbed - purely cosmetic but the fundamentals of that car look great.
http://www.autotrader.co.uk/classified/advert/201610038382066?postcode=nw71js&onesearchad=Used&onesearchad=Nearly%20New&onesearchad=New&advertising-location=at_cars&year-to=2008&make=BMW&year-from=2006&sort=price-asc&radius=1500&minimum-badge-engine-size=3.0&model=Z4&page=1