At the Frankfurt Motor Show in 1955, BMW->ke178 unveiled an all new sports car that was put in place to help continue the company's post-war growth. The 503, as BMW dubbed it, went into production the next year and came in both a coupe and convertible model. Only 413 total 503->ke317 models were ever built and 139 of those were convertibles (cabriolet).

This makes the BMW 503 Series I Cabriolet one of the most desired BMWs of both its era and all eras, for that matter. The 503 was never an overly powerful model, but it was a well-balanced car that delivered performance and comfort at the same time – something that was lacking in the late-1950s.

With it only seeing a production run up until 1959, getting your hands on one of these gems is quite the tough task. It is not completely impossible, however, as there are a few that cross the auction block every handful of years. You can bet your bottom dollar on the fact that these rare 2+2 drop-tops fetch a rather hefty sum.

Click past the jump to read all about the 1956 through 1959 BMW 503 Series I Cabriolet.

bmw-503-series-i-cabriolet

Specifications
  • Make: Array
  • Model: bmw-503-series-i-cabriolet
Pros
Cons

1956 - 1959 BMW 503 Series I Cabriolet

Specifications
  • Make: Array
  • Model: 1956 - 1959 BMW 503 Series I Cabriolet
  • Engine/Motor: V8
  • Horsepower: 140 @ 4800
  • Torque: 159 @ 3800
  • Transmission: 4-speed manual
  • [do not use] Vehicle Model: Array
Pros
Cons

Exterior

The 503 definitely boasted one of the more advanced designs in a production 1950's car. Up front, it has one slim vertical grille flanked by two smaller, horizontal grilles. The large, round headlights seat into rounded fenders that trace the entire length of the car's front fenders. The thin, chrome bumper under the front end provided little protection, but it looked good providing the little protection that it gave.

The hood has a very slow slope to it, giving the front end a more aerodynamic look. Down the center of the hood you get a chrome strip that divides the hood into two halves. This brings you to the steep windshield that offers little aerodynamic benefit, and is surrounded by chrome trim.

In an attempt to break up the monotony of the rather plain side of the car, BMW ran a chrome strip from aft to tail. This strip had a slight curve to it and a sharper upward turn near the rear of the 503, helping it achieve the task of sprucing up the car's otherwise bland side profile. In what looks to be a connector between the front and rear bumpers, BMW added a chrome strip on the bottom of the car's side that runs from one wheel well to the other.

The back end boasts fender flares similar to those on the front, but slightly thinner. A chrome applique just above the license plate helps to keep the rear end from becoming dull. The 503's backside boasts four light sets: one taillight and brake light combination and one reverse light. The taillight and brake light have a sharp, chrome applique separating them.

Also on the rear end is an odd positioning of the muffler. BMW, in a fit of “where do we stick this” bolted the muffle to the body, just under the bumper, in plain sight. We can only assume that Bimmer ran out of space under the car.

Interior

The inside of the BMW 503 boasted two front bucket seats and a small, 2-seat jumper in the rear. To call it a 2-seat jumper is a little generous, but that was its intention. The features were very basic, as were most 1950's cars. It did, however, boast a Becker Mexico AM radio, something not yet standard in every car built.

Engine and Transmission

The main concern for the 503 was to rid BMW of its aging 2.0-liter 6-cylinder engine. BMW manufactured the 503 to handle an all-new, aluminum block 3.2-liter V-8 engine with twin Zenith carbs that pumped out 140 horsepower at 4,800 rpm and 159 pound-feet of torque at 3,800 horsepower. Those aren't staggering numbers, but in its time, they were pretty respectable for a small-displacement V-8.

The engine connected to a 4-speed transmission that, as expected, threw power to just the rear wheels.

This combination could push the 503 to 60 mph in 12.8 seconds and gave it a top speed of 118 mph. Again, those aren't impressive numbers by today's standards, but by the late-1950s, those were very respectable numbers for a small roadster.

Pricing

Like we always say with collectable and classic cars, they are worth exactly how much someone will pay for them. NADA books out a high retail value of about $137,000 for a base model 503 cabriolet. In real life, however, collectors are wiling to pony up a little more dough, as RM Auctions is selling a fully restored 1956 503 Series I cabriolet at auction and they anticipate it to go for $325,000 to $425,000.

Conclusion

While the BMW 503 was not an overly fast or powerful car by today's standards, it was very respectable for its era. In addition to that, it is also a key element in BMW's return to glory following WWII. To boot, it is one of the rarest BMWs in the world, especially the cabriolet model.