Regular fuel used Lexus rx350

Nevada makes an excellent point

Many people get the cylinder layout wrong on Toyota and Lexus vehicles

Here is a document which lists the cylinder layout for the 2GR-FE V6, which you have

Toyota’s layout is not like GM, Ford, or even most european vehicles

I wouldn’t be at all surprised if he replaced #6 coil and plug, thinking it was #5

I’m not being a spoiler

It’s just that I’ve seen these things happen quite frequentyly

Since this is a Lexus dealer, it seems like the mechanic would be more familiar with the Toyota layout than that of other manufacturers.