The ZSPEC "Stage 3" Dress Up Bolts® Fastener Kit for '17-18 Hyundai Elantra covers virtually everything visible under the hood and some items outside. 

The kit covers the following areas

Fenders
Coolant Overflow Reservoir & Bracket
Hood Prop
Sensors on Valve Cover
Wiring Harness Bracket (on Valve Cover)
Hood Latch
Trunk Striker (in Trunk Area)
Fuel Door Area - Filler Tube & Door
Headlights
Fuse Box
Ground Strap
Shock Towers
Throttle Body
Battery Terminal Nuts
Battery Lock Down
Plastic Intake Mnaifold
Valve Cover
Coil Packs
High Pressure Fuel Unit
Hood Hinges
Sensor on Intake
Alternator Bracket
Misc. extras for custom needs.

Top quality A2-70 (SU304) Stainless Fasteners
Billet Aluminum Finish Washers
Bagged and Labeled by function to ease installation.
Basic installation guide included.
Requires basic hand-tools for installation (not included).