The Ecto-1a was an updated version of the Ecto-1 that the Ghostbusters used to travel. This vehicle appears in the film Ghostbusters II and many issues of Volume One and Two of the Ongoing IDW Comic Series.
The Ghostbusters had put improvements on Ecto-1 with more technical equipment. One of the most noticeable upgrades was a digital announcement board running down either side of the vehicle's roof broadcasting Ghostbuster advertisements, specials, and their phone number, JL5-2020 or 555-2020. Also, the logo was updated on the doors and back entrance of the ambulance, and was put on the hood.
Secondary Canon History
After the "Infestation" event, the Ghostbusters switched from their Ecto-1 look back to Ecto-1a with a few tweaks, such as keeping the classic No Ghost logo. Ecto-1a was taken along by the Ghostbusters on their summer cross country trip across America. It was rear ended when Peter and Laura Parr were attacked by the Phantom Truck Driver. Luckily, a Super Slammer Muon Trap was attached to the roof for the trip. On Peter's cue, Laura opened the trap and the phantom was captured. Once the Ghostbusters returned to New York, Ray Stantz and Winston Zeddemore began maintenance on Ecto-1a. The next year, the New Ghostbusters used Ecto-1a for a little over three months while the Ghostbusters were imprisoned in the Collectors' Limbo. Kylie Griffin drove Ecto-1a to the Parkview Psychiatric Hospital for a consultation that turned into a confrontation with Idulnas and The Collectors. In November, on the night of the Day of the Dead, Ecto-1a's roof was slashed up by a projection of Santa Muerte. Winston was visibly angered by the attack and shot the projection, causing it to split into two.
- Ecto-1a was originally scripted as Ecto-2, and one reference to this remains in the movie. When Dr. Venkman is standing outside of his apartment and the car pulls up, the phrase "Ecto-2" is visible on the license plate.
- In a deleted scene set after Chapter 16: Vigo 101, a Vigo-possessed Ray tried to kill the Ghostbusters while driving Ecto-1a. At the last second, Winston punched Ray and jammed the brake. Instead of a lethal crash, Ecto-1a skidded into a tree.
- In a deleted scene that would have introduced Louis Tully's cousin Sherman Tully. It was revealed Sherman helped get the Ghostbusters released from Parkview Psychiatric Hospital. One of the conditions was he would get to ride in Ecto-1a.
- In the 11/27/88 draft, Louis filled up the car's gas tank with Super Unleaded, 20 cents more than Regular, and put it on his own credit card. 
- As part of Kenner's The Real Ghostbusters Toy Line, an animated version of Ecto-1a was part of the ninth wave of toys.
- Later, Jocsa reissued the Kenner vehicle and also released a version with working lights and sound based off the previous version.
- The design for the Chicago Ghostbusters' Ecto-15 is partly based on Benton Jew's Ectomobile concept art.
- On Subscription Cover A of Ghostbusters 101 #1, Ecto-1a appears in place of the DeLorean in the homage to "Back to the Future".
- The phone number on Ecto-1a sports an extra "0" after "JL"
- On page 383 of Ghostbusters: Interdimensional Cross-Rip, Ecto-1a appears.
- On Cover A of Ghostbusters Crossing Over Issue #1, Garrett Miller is sitting in Ecto-1a.
- Spook Central (Fan Site)Ghostbusters II Script February 27, 1989 (Page 46): "The garage door opens and the new improved ECTOMOBILE comes ROARING out onto the street, its ghostly SIREN MOANING and WAILING."
- Spook Central 2/27/89 script
- Ghostbusters II
- Ongoing Series
- Volume 1
- Volume 2