Get custom parts or universal parts.
obvioulsly unless you're willing to spend loadsa money don't expect anything to outstanding, but it easy to keep things sexy and neat for less.
There are Universal BMW M3 Skirts
Front Corner Splitters and full Splitters
Modifying an old Tipo bumper chopping it in two and attaching it to your
existing bumper to make a "unique" splitter (I've seen a pic looks nice)
Rear Splitters
Modifying your back bumper by sticking something to it (hav'nt thought of what yet)
Several Tipo Spoilers are still available from various web sites I'll post links later.
Search on the ol' Internet for
TIPO STYLING
TIPO MODIFYING
TIPO MODIFICATIONS
TIPO CUSTOMISATIONS
TIPO SPOILERS
TIPO SIDE SKIRTS
TIPO BODY KITS
UNIVERSAL SPOILERS
UNIVERSAL SIDE SKIRTS
UNIVERSAL BODY KITS
you'll find stuff out there specially in the skirts and spoiler department.
Have a look here, my Tipo and Another members Tipo, all neatly rolled into one Thread, and before you ask yeah I wanted the body kit painted black
https://www.fiatforum.com/showthread.php?t=27618