Aftermarket alarm system

[Love my Lexus]

What is the best alarm system to have installed in a 2016 nx300h? Can this be installed without splicing into electrical ?

[DanD]

Why? - your NX already has an alarm system...

[LenT]

16 hours ago, DanD said:

Why? - your NX already has an alarm system...

This seems a fair point!  Of course you do need to ensure that it’s actually activated.

But as you appear concerned to avoid a system that’s integrated into the electrical system, then that surely eliminates an alarm system anyway.  Even the latest, highly sophisticated, programmable immobiliser systems (eg the Ghost Immobiliser) have to be introduced into the wiring loom somewhere.

Have you considered a visible theft deterrent?

Of these, the best is probably the Disklok Steering Lock that completely covers the wheel and I don’t recall any destructive test that succeeded in removing it within ten minutes.  If someone wanted your car that badly, they would probably have to drag it onto a trailer!
 

https://www.autoexpress.co.uk/product-group-tests/95031/best-steering-wheel-locks-2021