Mods and Warranties: Okay or no?

[Yaris Revenge]

Since I'm seriously considering a purchase now, I'm also daydreaming about mods. One of the first would be the lowering springs, I'm sure. Here's my question: does it interfere with the warranty if you install a brand other than TRD springs? From what I've found here on Yarisworld, I'd probably want the NFs instead, but not if it's gonna' void the warranty.

Likewise with adding a tach... does tinkering with the electronics in such a way void the warranty?

Thanks,

~YR

BTW, also looking for advice on tire/rim sizes to use with a lowered Yaris. I think 16" rims are as big as I'd want to go, but I have no clue about what kinds of offset and width I should be looking for. NO scrubbing allowed!

[Yaris Revenge]

Awesome, thanks for the link!
~YR

[Kaotic Lazagna]

yeah, that's what i heard too, but i made an "ananomous" phone call to the dealer i bought my yaris from and asked, and they said that any mod will void your warranty. lol....still bought springs, struts, and a strut bar tho. as long as i have my powertrain warranty, i'm fine.