McLaren has delayed U.S. deliveries of the plug-in hybrid Artura once again, meaning owners will have to wait at least another four months before picking up the keys to the car.

A memo recently sent out to McLaren’s retailers in the U.S. reveals that the delay has been triggered by the carmaker introducing “enhanced testing procedures” that are said to provide “additional checks and testing in our quality control procedure.” McLaren spokesman Roger Ormisher confirmed the news while speaking with Auto News.

“To implement these quality control procedures, we have temporarily slowed production,” he said.

 McLaren Delays U.S. Deliveries Of Some Arturas Once Again

The delay means that customers who originally promised their Artura in May will now have to wait until September.

While the Artura has landed in some markets, local launches of it have been delayed on multiple occasions. In late 2021, it was delayed for the third time following McLaren’s decision to prioritize limited semiconductor supplies to higher-margin models including the Elva and 765LT Spider. This delay came just a few months after the company told U.S. customers that issues with software suppliers had delayed it until late August or early September. Fast forward almost two years and many have been delayed again.

Read: The McLaren Artura Gives You 671 Reasons To Love Its Plug-In Hybrid Powertrain

There are some McLaren Artura models that have touched down in the U.S. but not even they are trouble-free. In December last year, it was revealed that 164 U.S. examples had to be recalled because the nuts used for the high-pressure fuel pipe could come loose over time, potentially triggering a fuel leak and a fire.

On paper, the Artura is quite a compelling package. It is powered by a 3.0-liter twin-turbocharged V6 supplemented by an electric motor and a 7.4 kWh battery pack. It produces a combined 671 hp and 531 lb-ft (720 Nm) of torque and can hit 62 mph (100 km/h) in 3.0 seconds and an electronically limited top speed of 205 mph (330 km/h).

 McLaren Delays U.S. Deliveries Of Some Arturas Once Again