Buying a Convertible or Roadster: Summer Guide

Top-Down Season Is Back

As summer approaches, demand for convertibles and roadsters rises noticeably. Anyone buying smart now can enjoy months of wind and sun. But this is also the season when the typical weak spots of open-top cars surface: top seals, hydraulic pumps, and chassis flex. We’ll show you what to look for and which models currently offer the best value.

Current Market Data (May 2026)

Our database shows the following picture for the most popular open-top classics:

Model	Avg Price	Price Range	Listings	Trend (12 mo)
BMW Z3	€15,346	€3,800 – €52,750	93	slightly down (-€4,074)
BMW Z4 E85	€12,534	€3,500 – €29,999	35	rising (+€27,335)
Mercedes R129 SL	€26,202	€6,499 – €52,241	65	falling (-€38,557)
Mercedes R107 SL	€35,009	€4,490 – €79,995	62	slightly down (-€6,598)
Mazda MX-5 NA	€14,871	€12,000 – €16,900	7	slightly down

The data paints a clear picture: the Z4 E85 is an emerging classic, the R107 remains a long-term value hold, while the R129 and Z3 currently offer strong entry opportunities.

Step-by-Step to the Right Convertible

Step 1: Define Your Use Case

Before settling on a model, answer these questions honestly:

Weekend toy or daily driver? An R107 with a €35,000 investment deserves careful handling, while a Z3 works perfectly well as a daily driver.
Driving pleasure or value preservation? The R107 and Z3 M Roadster trend upward in value, while a regular Z4 E85 is still in a buyer’s market.
Two seats enough? Roadsters like the Z3, Z4, and MX-5 are pure two-seaters. Anyone needing to bring family along should consider the R129 or a 4-seat cabriolet.

Step 2: Inspect the Top Thoroughly

The top is the most expensive wear item on any convertible. Replacement costs run from €1,500 to €4,500 depending on the model.

Soft top (Z3, MX-5, R129 until 2001):

Check the folds for cracks
Inspect the rear window for scratches and yellowing
Examine seal strips along the frame
Test with a garden hose to verify the cabin stays dry

Hardtop or folding metal roof (R129 coupe-cabrio, R230):

The hydraulic pump must run quietly and evenly
Verify all end-position switches
Front and rear latches must not stick
Test full open-close cycles at least three times

Step 3: Body and Rust

Open-top cars are more prone to water ingress and corrosion than sedans. Critical points:

Sills: Notorious on the R107, hidden under plastic trim on the Z3
Rear wheel arches: Classic rust traps on R107 and R129
Trunk area: Often leaks on Z3 and Z4
Top storage well floor: Water collects readily in the rear corners

With a Mercedes R107 averaging €35,009, the premium for a rust-free example almost always pays off. A cheap entry at €4,490 typically ends in an expensive restoration.

Step 4: Mechanical Test Drive

During the test drive, target these checks specifically:

Chassis flex: Listen for creaks and rattles over bumps
Steering precision: Roadsters should feel direct and play-free
Straight-line tracking: Test on motorway stretches
Brake behavior: Check both stationary and at 100 km/h
Drive both top-down AND top-up: Compare noise levels

Seasonal Tips for the Summer Market

Why May and June Are a Particular Phase

In May, prices traditionally sit at their annual peak. Sellers know about demand and price accordingly. Buying now still pays off for two reasons:

Immediate utility: A convertible bought in July only leaves three sunny months before winter storage
Real-world test drives: At 25 °C you can properly evaluate the AC, behavior with the top down, and overheating tendencies

Where the Deals Sit Right Now

Our data shows the R129 trending downward by -€38,557 year-on-year, putting it firmly in a buyer’s market. Anyone looking for a Mercedes R129 currently has 65 active listings to choose from and room to negotiate.

The BMW Z3 is also widely available with 93 listings. The broad selection lets you find the right car rather than settling for what’s available.

Three Clear Recommendations

For Entrants: BMW Z3 or Mazda MX-5

At an average of €15,346, the BMW Z3 offers an affordable entry into the roadster world. Maintenance is manageable and parts availability is excellent.

Suited for: First-time convertible buyers, weekend drivers, younger enthusiasts

For Comfort Seekers: Mercedes R129

The Mercedes R129 at an average €26,202 is the ideal choice for longer tours. Hardtop for winter, soft top for summer, and V8 options for high-mileage drivers.

Suited for: Comfort lovers, long-distance drivers, classic collectors

For Value Retention: Mercedes R107

The R107 is the only option presented here promising stable to rising long-term prices. At €35,009 on average you pay more, but you buy a proven investment.

Suited for: Collectors, lovers of timeless design, long-term owners

Before Purchase: Workshop Inspection

Invest €150–€250 in a professional pre-purchase inspection. For convertibles specifically, ask the workshop to check:

Top mechanism and hydraulics
Chassis flex on a lift
Underbody and sills
Top storage well for water damage
Seat and interior condition (sun damage)

Pre-Contract Checklist

Top fully opened and closed three times
Water test with hose performed
Test drive completed top-up and top-down
Body inspected on a lift
Service book and maintenance history complete
TÜV / MOT reports for the last 6 years reviewed
Price compared with our market average
Insurance quote (seasonal plate) obtained in advance

Conclusion

Summer 2026 offers an interesting market picture for convertible buyers. While the BMW Z3 and Mercedes R129 currently sit in a buyer’s market, the R107 and Z4 E85 remain value-stable. Anyone buying now should focus on the top, body, and test drive — and then nothing stands in the way of an enjoyable summer.

Our recommendation: start with the BMW Z3 or Mercedes R129 if you value selection and negotiating room. Anyone thinking long-term should look at the R107.

Current prices and trends are available on the model pages BMW Z3, BMW Z4 E85, Mercedes R129 and Mercedes R107.