I've gone through half dozen sets of LED underglow over the years. Some were dim some were intensely bright. Thy're a PITA to wire & hide the wireing properly too. And they can be pretty tacky if you don't hide the tubes . If your car is lowered you may as well say goodby to the tubes. You will eventually crack them on something. I sure did. Honestly they are a waste of money unless you have an undercarriage to show off at a car show.
We mod GPs.....
1978 F250 2wd (460 c.i.d. / C6)- soon to give up the powerplant to an '80-'86 F150
White 2000 Grand Prix GT coupe One still slow and loud... other one scoots just a bit.