The Ectomobiles share various pieces of equipment but are unique to each car. These pieces create the aura that is one of the most iconic movie cars ever made. Many different versions pre-production were proposed configured in various ways, from multiple whip antennae to "gumball" rotating lights.
The lightbar used on the Ecto-1 is a Code 3 Force 4 XL 48" lightbar, while the Ecto-1A uses two different model lightbars. One of the models is the same Code 3 Force 4 XL 53" lightbar that was used on the Ecto-1. However, clear lenses with colored filters on the rotators were used on these bars. The color order on the front bar from passenger side to driver side is amber, red, green, red, green, amber. The rear bar keeps the same order, except with blue fliters replacing the red ones. The other bar used is a Whelen Edge 9000 bar. This bar also uses blue, amber and green as the colors on the bar.
The red beacon on the Ecto-1 is a Federal Signal Model 19 "Propelloray". The Ecto-1A uses a Code 3 model 550 red beacon on top of the rack which is still readily available for purchase. The 1A also uses an amber beacon in the grill. This beacon is a first generation Code 3 Dashlaser.
Both of the Ectomobiles use two different types of strobe lights. The strobe on the roof rack for both cars is a Whelen HRDF-200. This model has been replaced with the modern HRF-CA. The other strobe used on the Ecto-1 bumper is a Grimes anti-collision strobe. The 1A used the replacement for Grimes anti-collision strobe on the bumper which a Whelen version. This part has since been replaced with an LED model.
The Ecto-1 features a Unity brand model S6 spotlight with an optional mirror as part of the light housing. The 1A also has the same model spotlight, however does not have a mirror. To properly mount this light on the car, part number 138L must be used. Both the S6 and 138 are still available from Unity, however they do not offer a housing that includes a mirror. Both versions of the Ectomobile use 4 deck lights. These lights are size par 46, which is a 6" diameter. Currently Grote offers this style of lamp housing via their website. The 1A also features a directional arrow stick, a Code 3 AS-10 and an indeterminate model third brake light. While not a light, the Ecto-1 also has a Federal Signal C5GB coaster siren. This is also another part that Federal discontinued many years ago, however is not as difficult to find as the Propelloray as they appear on eBay more frequently.
The roof rack on both cars is 72" and 36" wide, while the height of the 1A's rack is unknown. Both racks feature two A-6 oxygen tanks used by World War II-era fighter planes and bombers. The colors of the tanks are yellow on the 1 and white on the 1A. The racks also feature a schedule 40 PVC pipe that is 53" long and has a 6" inner diameter. The only differences are the 1's storage tube features a pea green color and the 1A's tube sports an orange color. Both racks also feature a 6"x9" radome and a 18" diameter quarter hemishpere radar dish mounted to a saw mandrel at the rear. The last pieces both racks share are a large heat sink toward the rear of the rack and two smaller heat sinks mounted to the wooden box portion of the rack on the front. The racks also share a similar looking metal box with black hoses on the passenger side, but they are in actuality quite different. Unique parts on the cars are a Texas Instruments Cross-Section Sensitivity Unit variant ASR-5, a "Sniffer Tower", a stainless steel tank with what appears to be a distribution block for its contents attached to it, a green box with a metal strip that sits on top of a box that is similar to the HVAC box on the 1's rack, a US Navy sonobuoy on the driver's side above the oxygen tanks and a very large satellite dish that takes place of the Sniffer Tower and of course two approximately 76"x 10" green/red light sign boards. These boards were used to advertise the Ghostbusters return to business and that they were for hire among other phrases.
There are vast differences between the two Ectomobiles in terms of interior components. No two parts are shared and the parts inside both cars are even more difficult to find than their exterior component counterparts. The pieces found in the Ecto-1 are overwhelmingly avionics while only a few select pieces are aviation related on the 1A. The front passenger compartment of the Ecto-1 contains only four parts. The first is a police scanner made by Regency, model ACT-R 20/6. The second piece is is dummy load antenna, model 525 made by Gentec. The third part is a five-panel panoramic rear view mirror. Finally there is a citizen's band radio made by Midland, model 77-859. All of these parts save the mirror aren't produced anymore but do appear on eBay everyonce in a while and are available from various surplus electronics retailers from time to time. The rear compartment of the Ecto-1 contains 15 pieces. Like the rest of the Ecto-1A, there is little known about the interior pieces of the car other than what can be discerned from pictures. With that the very limited list of known parts of the 1A are an cathode ray tube PC monitor and keyboard, a ID-1732/AYQ-5 multipurpose/special computer known as a "comfy gator", a TRIO-TECH Ambient Tester and A-528 and a regulator relief valve.
The Ecto-1 also features three sets of louvers, two on the hood and one on the rear door. Additionally there are two 100" whip antennae mounted to the car, one on the passenger fender and the on the driver's quarter panel. There are also two blue RV sewage tubes attached to the driver's side and a gray liquitite conduit on the passenger side. For the Ecto-1A, there is a large cylinder on the back of the roof that a steel-braided hose runs from next to the blues hoses. The rear bumper of the 1A is replaced with a custom diamond-plate version.