diff --git a/site/src/content/docs/index.mdx b/site/src/content/docs/index.mdx
index eca30cc..9fa729f 100644
--- a/site/src/content/docs/index.mdx
+++ b/site/src/content/docs/index.mdx
@@ -1,16 +1,16 @@
 ---
 title: K-Line
-description: BMW I/K-Bus + OBD-II K-line interface for ESP32 with PC817 optocoupler isolation
+description: "ESP32 K-line interface for automotive diagnostics and module control — BMW I/K-Bus, Ford, Honda, Toyota, VW, and 400+ vehicles"
 template: splash
 hero:
-  tagline: Multi-protocol automotive bus library for ESP32. Optocoupler-isolated hardware interface with SPICE-validated circuit design.
+  tagline: "ESP32 interface for automotive K-line buses. Read diagnostics, control modules, and talk to ECUs across hundreds of vehicles — with optocoupler isolation and SPICE-validated circuit design."
   actions:
+    - text: Vehicle Compatibility
+      link: /reference/vehicle-compatibility/
+      icon: right-arrow
     - text: Circuit Design
       link: /reference/circuit-design/
       icon: right-arrow
-    - text: Firmware Architecture
-      link: /reference/architecture/
-      icon: right-arrow
       variant: minimal
     - text: Source Code
       link: https://git.supported.systems/warehack.ing/i-k-bus-board
@@ -18,38 +18,44 @@ hero:
       variant: minimal
 ---
 
-import { Card, CardGrid } from '@astrojs/starlight/components';
+import { Card, CardGrid, LinkCard } from '@astrojs/starlight/components';
 
-## What is this?
+## Two protocols, one board
 
-An ESP32-based interface board for talking to BMW's proprietary body/instrumentation bus (I-Bus and K-Bus) and OBD-II K-line diagnostic ports. Uses PC817 optocouplers for galvanic isolation from the vehicle's 12V electrical system.
+K-Line is an ESP32 library and hardware interface for the single-wire buses found in cars from the mid-90s through late 2000s. It handles two distinct protocols that share the same physical layer:
 
-The firmware library — **K-Line** — handles both protocols through a shared transport layer, with separate protocol handlers for BMW's multi-master bus and OBD-II's master/slave diagnostic sessions.
+- **BMW I/K-Bus** — the body control network on E31 through E87 chassis. Lights, locks, windows, climate, steering wheel controls, instrument cluster. Multi-master, 9600 baud.
+- **OBD-II K-line** — the ISO 9141 / ISO 14230 diagnostic protocol used by Ford, Honda, Toyota, VW, Chrysler, and dozens more. Read PIDs, clear DTCs, talk to ECUs. Master/slave, 10400 baud.
+
+The hardware uses PC817 optocouplers for galvanic isolation between the ESP32 and the vehicle's 12V electrical system. The circuit is SPICE-validated — every signal path simulated in LTspice before soldering.
 
 <CardGrid>
-  <Card title="Two Protocols, One Board" icon="setting">
-    BMW I/K-Bus (9600 baud, 8E1, XOR checksum) and OBD-II K-line (10400 baud, 8N1, mod256 checksum) share the same physical layer but have completely different framing and initialization. K-Line handles both.
+  <Card title="400+ Vehicles" icon="open-book">
+    BMW, Ford, Honda, Toyota, VW, Audi, Mercedes, Volvo, Subaru, Mazda, Hyundai, Kia, Chrysler, and more. Any car with ISO 9141 or KWP2000 diagnostics.
   </Card>
   <Card title="SPICE Validated" icon="approve-check">
-    Every circuit path simulated in LTspice before soldering. Three parameter sweeps identified the R2=220 ohm fix for 3.3V ESP32 compatibility. Six netlists document the full operating envelope.
+    Eight netlists cover both signal paths, three parameter sweeps, and two bus impedance scenarios. The R2=220 ohm fix for 3.3V ESP32 was found through simulation, not guesswork.
   </Card>
-  <Card title="Code Reviewed" icon="warning">
-    Two rounds of code review caught concurrency bugs (64-bit torn reads, TX loopback race), protocol issues (UART pin detach no-op, timeout underflow), and missing safety checks. All fixed.
+  <Card title="Reviewed and Hardened" icon="warning">
+    Two code review rounds caught ISR race conditions, protocol framing bugs, and timeout underflows. Defensive design throughout — checksums validated, echo verified, sessions kept alive.
   </Card>
   <Card title="Three ESP32 Variants" icon="laptop">
-    Builds for ESP32 (Xtensa), ESP32-C3 (RISC-V), and ESP32-S3. PlatformIO project with per-board pin overrides.
+    Builds for ESP32 (Xtensa), ESP32-C3 (RISC-V), and ESP32-S3. PlatformIO project with per-board pin configuration.
   </Card>
 </CardGrid>
 
-## Supported Vehicles
+## Supported vehicles
 
-**BMW I/K-Bus:** E31 (8 Series), E38 (7 Series), E39 (5 Series), E46 (3 Series), E52 (Z8), E53 (X5), E83 (X3), E85 (Z4), E87 (1 Series)
+<CardGrid>
+  <LinkCard title="BMW I/K-Bus" description="E31, E38, E39, E46, E52, E53, E83, E85, E87 — plus MINI R50/R52/R53 and Range Rover P38A" href="/reference/vehicle-compatibility/#bmw-i-bus-and-k-bus" />
+  <LinkCard title="European" description="Ford Fiesta/Focus/Mondeo, VW Golf/Passat, Audi A4/A6, Mercedes C/E-Class, Volvo S60/V70, Fiat, Alfa Romeo, Peugeot, Renault, Opel" href="/reference/vehicle-compatibility/#k-line-by-manufacturer" />
+  <LinkCard title="Japanese" description="Honda Civic/Accord, Toyota Corolla/Camry, Nissan Altima/Sentra, Mazda3/MX-5, Subaru Impreza/Legacy, Mitsubishi Lancer" href="/reference/vehicle-compatibility/#k-line-by-manufacturer" />
+  <LinkCard title="Korean and American" description="Hyundai Elantra/Sonata, Kia Optima/Sorento, Chrysler/Dodge/Jeep — Wrangler, Cherokee, Ram, Neon, PT Cruiser" href="/reference/vehicle-compatibility/#k-line-by-manufacturer" />
+</CardGrid>
 
-**OBD-II K-line:** Any vehicle using ISO 9141-2 or ISO 14230-4 (KWP2000) diagnostic protocols
+## Project status
 
-## Project Status
-
-Hardware circuit is SPICE-validated. Firmware builds clean across all environments. Next steps: breadboard prototype, loopback testing, and vehicle testing.
+Hardware circuit is SPICE-validated. Firmware builds clean across all three ESP32 environments. Next: breadboard prototype, loopback testing, and vehicle testing on BMW E46 K-Bus and Ford Fiesta K-line.
 
 ## Attribution