HOW TO GET ONE IN YOUR GARAGE

An expert’s view DAVID SMITHERAM, BMW CAR CLUB OF GREAT BRITAIN

“I own a 2006 Roadster that’s done 55,000 miles. I work in motor racing and for many years saw how fast and reliable the old M3 E46s were and how easily they doubled as road and track cars. It got me thinking about the Z4 M, the last BMW sports car with a manual gearbox and a naturally aspirated straight-six. Mine’s a Roadster, so I’m bound to say it’s the one to buy, but since the car was designed as an open-top, it feels almost as stiff as the Coupé. Prices are softer too, and it’s more fun in the sun.”

Buyer beware… ENGINE

Oil and filter change every 7500 miles would be nice to see. Initial running-in service not as crucial as claimed as long as subsequent services are kept up. Inspection II service requires valve clearance check. Some cases of failed conrod bearings beyond 75k miles. Budget for toughened replacements as a precaution. If idle is lumpy, check and clean idle control valve. Check condition of engine mount bolts, which have been known to fracture.

SUSPENSION AND BRAKES

Rear trailing arm bushes begin to wear at 50k miles, leading to uneven tyre wear; front bushes give less trouble. Rear springs can snap – fit thicker, lower Eibach replacements. Ride is unaffected because it’s already rock-hard. Brakes can feel dead but aftermarket pads fix it. Standard pads are okay on road but not for track use.

BODY

On Roadsters, crouch down, find the roof drain holes and check for blockages. A wire coat hanger should clear obstructions. On Coupés, check for corrosion on the underside of the bootlid caused by water collecting in the scoop between it and the rear window. Poor accident repairs aside, it’s the only place Z4 Ms rot. Check rear centre brake light works (its securing screws are often too tight).

INTERIOR

Expect wear on door handles, switches and driver’s side seat bolster, and check electric windows work (regulators can be troublesome).

Also worth knowing

BMW protected the roadster’s roof motor in a watertight container (it’s on the passenger side of the car) but if the roof’s drain holes become blocked, water enters it and the motor packs up. Fortunately, those clever blokes at the BMW Car Club have a fix that involves relocating it out of harm’s way.

How much to spend £12,000-£13,495

Private-sale 2006 Roadsters with 90k-plus miles start here, although guide auction price for average cars at this age is around £7000.

£13,995-£15,495

Still strong money for 06- and 07-plate Roadsters with mileages around 65k.

£15,995-£17,495

More 06-07 Roadsters with sub-50k mileages.

£17,500-£19,995

Wide choice of 06-07 Coupés with around 70,000 miles.

£20,000-£25,000

Includes a couple of main dealer cars – a 36k-mile 06 Coupé for £21,000 and a 34k-mile 07 Roadster for £22,990. Higher up the price ladder is a 16k-mile 08 roadster for £24,950.

One we found BMW Z4 M, 2007/07, 74,000 MILES, £13,999

A private sale, so you can get the measure of its keeper and how they’ve cared for it. Full BMW history and the roof motor has been relocated out of harm’s way. It has a performance exhaust but the original will come with it. A few scuffs, otherwise worth a look.