Published: June 01. 2010 2:00AM

By Dan Byers
CONTRIBUTING WRITER

Summer is a season for adventure, and a season for fun. But it’s also a season for change. We embrace the spirit of the summer by shedding the weight of winter. We shed pounds to prepare for the beach and shed sweaters to prepare for the heat.

But summer isn’t just vacation season, it’s also driving season. And one of the best ways to embrace driving season is to experience it in its most elemental form — behind the wheel of a true open-top sports car. Regardless of the temperature outside, thermometers are bound to rise when one of these hot new sports cars drives into view.

2011 Porsche Boxster Spyder

As a direct descendant of the iconic 550 Spyder, the new Boxster Spyder was born with the instincts, reflexes and genetic makeup of a true motoring legend. But good genes can only take you so far. Fortunately, the engineers at Porsche left nothing to chance, combining the authenticity of the past with the performance and power of a modern sports car.

Even the most casual glance reveals the car’s intent. This is a car meant to be enjoyed with the top off. Unlike most modern convertibles, the Spyder’s canvas top is manually operated, offering simple, basic protection when Mother Nature doesn’t cooperate.

By dispensing with the power top, designers saved weight. This, along with other weight-saving measures, helps maximize performance and increase agility. The Spyder’s 3.4 liter direct injected flat-six generates 320 hp, launching the lightweight Porsche from 0 to 60 MPH is 4.6 seconds. A six-speed manual gearbox is standard, with the delightful seven-speed dual-clutch PDK transmission available as an option.

The interior perfectly matches the elegant, simple exterior in both color and design. Black interior elements are accented by a center console and dashboard trim that match the exterior color. Every component has its function, and comforts that don’t directly affect operation and performance have been eliminated. You won’t find door storage compartments, cup holders, or even an air conditioner (air conditioning is offered as an option however).

Independent suspension and a balanced mid-engine layout straighten out even the hottest corners, and a throaty exhaust note round out a package of pure sensory delight. Without question, the Boxster Spyder reflects the purpose of its design, offering an authentic roadster experience rarely found.

2011 BMW Z4 sDrive35is

Survival under the summer sun depends on how well we handle the heat. But sometimes the best survival technique is to generate more heat. With BMW’s Z4 sDrive35is, generating heat is as simple as touching a button.

Raising or lowering the Z4’s elegant hardtop only takes a handful of seconds, and the Z4 is that rare convertible that looks just as good in either position — top up or down. But if looks aren’t enough to generate heat, the Z4’s performance will.

The BMW Z4 sDrive35is is the fastest and best handling Z4 currently available. BMW’s famous twin-turbocharged, direct injection powerplant now produces 335 hp, up 35 hp from the previous model. 0 to 60 mph times are now just 4.7 seconds. The standard 7-speed Double-Clutch Transmission features launch control and paddle shifters, with a choice of automatic or manual gear selection.

The soundtrack to the Z4’s summer symphony is provided by a specially tuned exhaust system. A series of special baffles and mufflers gives the Z4’s voice a deep throaty rumble that’s a pleasure to hear.

M Sport upgrades such as adaptive M Suspension and interior enhancements such as a new thick-rimmed M leather steering wheel with gearshift paddles, an M driver’s footrest, and sport seats match the new engine’s performance, heating up the driving experience as thoroughly as the Z4 scorches the pavement.