All three cars are luxury cars.
All three cars are German.
All three cars get about 20 miles to the gallon.
All three cars are priced above $50,000.

The Audi S4 Convertible has a 340 horsepower 4.2 liter V8.
The Audi S4 Convertible has a base price of $60,450.
The Audi S4 Convertible's standard features include air conditioning w/dual-zone climate controls, interior air filter, tilt/telescopic leather-wrapped steering wheel w/radio controls, cruise control, heated 12-way power front seats, 6-disc CD changer, outside-temperature indicator, leather upholstery, heated front seats, power sunroof, satellite radio, and wireless cell phone link.
The Audi S4 Convertible gets from 0 to 60mph in 6.1 seconds (automatic) / 5.8 seconds (manual).

The BMW 335i Convertible has a 300 horsepower 3.0 liter V6.
The BMW 335i Convertible has a base price of $51,525.
The BMW 335i Convertible's standard features include air conditioning w/dual-zone climate controls, interior air filter, tilt/telescopic leather-wrapped steering wheel w/radio controls, cruise control, 10-way power driver seat, 8-way power passenger seat, memory system, passenger-side mirror tilt-down back-up aid, outside-temperature indicator, cooled center console, hardtop, leather upholstery, and premium sound system.
The BMW 335i Convertible gets from 0 to 60mph in 5.7 seconds.

The Mercedes-Benz CLK350 Convertible has a 268 horsepower 3.5 liter V6.
The Mercedes-Benz CLK350 Convertible has a base price of $56,975.
The Mercedes-Benz CLK350 Convertible's standard features include air conditioning w/dual-zone climate controls, interior air filter, power tilt/telescopic leather-wrapped steering wheel w/radio controls, leather upholstery, cruise control, 10-way power front seats, memory system, power-folding rear headrests, and outside-temperature indicator.
The Mercedes-Benz CLK350 Convertible gets from 0 to 60mph in 6.7 seconds.

Third place is the Mercedes. The 268 horsepower engine is behind the BMW's 300 horsepower engine and way behind the Audi's 340 horsepower engine. The Mercedes also takes 6.7 seconds to get to 60mph from a dead stop, which isn't as impressive as the other two cars. The CLK's interior is upscale and comfortable, and handling is absolutely exceptional. Though the ride quality was a little disappointing. The CLK is not behind the S4 and 335i by much, but I found it to be the least impressive of the three cars.

Second place is the Audi S4, very slightly behind the BMW 335i and very slightly ahead of the Mercedes CLK. I like the S4's long list of standard features (one being the 12-way power seats, considering that the CLK and 335i only have 8-way and 10-way power seats). Handling and ride quality are above average, but not by much. I also admire the S4's powerful engine - 340 horsepower V8 engine. The S4 is the only car of the three that has a V8. Fuel economy is 3-4 miles per gallon behind the 335i and CLK, though it's definitely worth it considering the S4's energetic and sporty nature, along with the powerful engine.

First place is the 335i convertible. It was a close competition. The 335i is the least expensive of the three cars, as well as the most fuel-efficient. The 335i is also the only car of the three with a standard cooled center console AND hardtop. Ride quality is average, though handling is great.

All three cars are good cars, but the 335i is king here. The Audi S4 was very satisfying, though not quite as good of a buy as the 335i. The CLK was somewhat disappointing and not real fuel-efficient.

What are your thoughts?

I'm gonna have to go with the S4. With that new forced induction 6 and quattro, I think it'll be more of a drivers car than the 335i. As far as the Benz goes, they're really only good if they're amg. Otherwise they tend to be expensive and heavy.

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2003 Ford Mustang SVT Cobra
4.6L DOHC V8 - 6 speed manual
520rwhp - 525rwtq at 16psi on stock blower
2002 Ford Mustang GT
4.6L V8 - 5 speed manual

My reflex reaction is to answer BMW 335i, but Audi is really polishing up their game. I am a huge fan of the LED parking lights they've been putting on all their vehicles. It gives their cars a mean look at the same time looking very high end.

If we were talking M3 then BMW would be the clear winner, but the the 335i can't quite best the new S4.

Like ApolloGT, I like all my Mercs from AMG.

Audi S4 for me.

Why do they have to be convertibles? To be real performance, it's gotta have a hard top. I'll take a B5 S4 with the 4.2, 6-speed, black, with Sportec Mono 10's, lowered to 25.25" ground to fender, true dual exhaust, full Porsche 911 brakes, clear corner headlights, smoked taillights, completely de-badged, and limo tint.

I might have already planned it out....

Whatev

I would also take the S4. Can't go wrong with a Quattro, though I would get the hard top over the cabrio. If I wanted a convertable I'd get a little roadster.

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2001 Chevrolet Monte Carlo SuperSport

good choice