Attaching light bar to 2016 RX350 roof rails

Can 1/4-inch shaft sheet metal screws* screwed into the roof rail be sufficient?
The police light bar mounts have two 1/4-incholes.
A pilot hole can be drilled straight down into the aluminum? roof rails, running from front to back right on the roof surface.

Thank you.

(*corrected lag bolts to sheet metal screws)

NO, just NO. Lag bolts are designed to screw into WOOD, not metal. So NO.

Pay a professional to install, these lights, Robert, this is clearly beyond your capabilities.

you may want to consider using rivets.

This person has been putting light bars on things for years and now he needs help ( More like he wants attention ) .

Besthathis expen$ive light bar donated by law enforcement not come off during a medical emergentransport.
Would prefer to bolt on withut and lock washer, but cannot get under or inside the roof rails.

How big do rivets get?

I meant sheet metal screws, not wood lag bolts.
But do sheet metal screws get big enough?
Would they work loose?

After a brush fire, the CP100 siren speaker came off our pumper’s roof as I was driving down a washboardirt road.
Had been professionally attached withree sheet metal screws.

Drop the headliner, drill thru the roof, attach with nyloc nuts and great big washers, use silicone rtv to seal the holes, 4 total 1/4 inch grade 5 bolts should get the job done, 6 is even better.

1/4 sheet metal self drilling screws would probably work if 6 were used but I’d prefer bolts and washers

What about bolting it to OEM crossbars?

Thank you. I always prefer bolts and lock washers.
Professionalsaid removing the headlinerequires also removing the pillar covers and gets to be a huge problem.

Now considering drilling a hole into the inside wall of the roof rail between where the bolts would fasten.
File hole into a rectangular opening. Insert nut and use a wire to position the nut beneathe hole drilled through the top of the rail.
Then screw the 1/4-20 bolthrough the light bar mount into eachut.

Good idea.
Letsuck says the crossbars are $300. And they curve up.

Wish I could get justhends of the crossbars which clamp to the roof rails and attach the light bar base to the clamps.

My only experience was with an Explorer, got the crossbars from a pick and pull salvage yard for $20.

Thank you. No salvage yards here have any.
Shall check some more.

Why not just drill the hole through the roof and headliner ?

If your going to butcher this Lexus up by drilling holes and putting a light bar on it, who cares what the inside looks like?

At the speeds you drive during emergency situations, you should use the most secure anchors possible.

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The light bar manufacturer said the same! Is why they don’t make attachments for Lexæ.
Not much “butchering”. The wires toperate the light bar will squeeze through the door gasket, so holes only in the roof rails.

(Just called for a 436-mile round trip non emergent mountaihospital bloodelivery.)

How about a metal plate going from the front roof rack to the back roof rack to mount the light to, then 2 h holes through the rack to bolt the plate down.

image Are they road legal?

There are aftermarket cross bars available that fit the roof rails on your RX starting at $120.

This used Letsuck has no roof rack crossmembers.
The police light bar has a sturdy metal base. Appears that If I mounthe light bar directly on the roof rails, the middle of the light bar will touch the convex roof.

Home Depot has this mirror mount nut which expands. 1/4-20 hex bolt screws into it.
Looks like it would fit into the hollow aluminum roof rack rail and expand righto the top inside of the rail.

We use rivet nuts to install luggage racks and running boards when they are anchored into sheet metal, the same can be used on your roof rails;

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Thank you! Sounds far stronger than my mirror mount nut.

Any you suggest?
Thank you.