Cohen entered the garage at 9 AM on the Saturday after passing through three Arab roadblocks, presented himself as an Arab fighter from Shchem and demanded that his vehicle (the first car expropriated in the Karyot belonged to a diplomat and the 'pencil' detonator was prepared by Yochai Bin-Nun who had to wake up a pharmicist on Friday nite to obtain the necessary chemicals) be attended to but the workers refused, suspecting it was what it actually was, a car bomb. He shouted that he was insulted and he was asked to wait for the manager. His car was already prepared to explode with 300 kgs. of dynamite packed in the trunk and and two additional mines set to explode if the an attempt would have been made to disarm the car. When after a short while he noticed that no one was paying him any attention, he activated the delay detonation mechanism and exited to join Shushan.
The Hagana car exploded and detonated the Arab car bomb vehicle resulting in 30 (or 5) Arab dead and some 70 wounded. In the escape, their car was blocked by an English army car that has stopped and blocked the street. After a search, which discovered nothing, the two were left to continue on their way.
The report from Davar the day after:
By the way, this wasn't the only action of this kind in Haifa. An incident occured on February 3. The bombing at Ben-Yehudah Street in Jerusalem by British deserters killed over 50.
By the way, this also happened in Haifa:
27 FEBRUARY 1948
Haifa, 1420 hours. Near the junction of the Qiryat Motzkin and the Haifa/Acre roads, Austin car No. M 118 was stolen by armed Jews when the passenger, a Mr. Thorne of C.R.L., stopped to buy a paper. These Jews surrounded Mr. Thorne and attempted to abduct him. Members of the Haganah then appeared on the scene and, together with Mr. Thome, fired on the would-be abductors who then made off in the car. The Haganah men escorted Thorne to C.R.L. An unconfirmed report states that one Haganah man was shot during this incident.