Post 2004 improvements?
Let's see:
Anti-collision radar that can detect almost every type of forward collision event (requires LKAS camera)
Lane keep assistance (love it or hate it)
Speed limit recognition and sign warning
360 degree cameras (all around parking view)
Advanced suspension, e.g. active dampers that respond to road conditions and driver input
Vehicle-to-X technology (detect stopped vehicles well ahead of radar, integrate with traffic light timing, etc.)
SOS/integrated e-Call with crash detection and backup battery (calls emergency services in the event of a severe accident, now standard on all cars)
Side collision radar (blind spot assist) - introduced in 2005 by Volvo, standard in higher trims from 2010-ish
Automatic parking function incl. parallel and bay parking
Apple CarPlay/Android Auto (better than integrated satnav in my opinion)
LED headlamps (love them or hate them)
Automatic headlights with dip/high beam assist (uses LKAS camera)
Matrix LED headlamps (uses LKAS camera)
Rear brake assist (stops car if you're reversing at low speed and sensors indicate a collision risk, standard on most cars now)
Reversing cameras (now standard on most cars, legal requirement in US/Canada)
Driver attention detection (with or without camera) (love it or hate it)
For EVs specifically:
Rapid charging that actually competes with petrol refill times
Larger batteries and range (Nissan Leaf 2012: 24kWh standard. 2026 Nissan Leaf 52kWh standard, 75kWh option. 2026 Nissan Micra EV has 40kWh standard and 52kWh option. Launch price for Micra is 50% lower in real terms than the Leaf.)
Greater net efficiency due to aero optimisations, e.g. active louvers
Pre-cooling/pre-heating on demand e.g. via phone app (excellent in winter, also good in summer!)
Integration of EVs with power grid allowing for dynamic load control/virtual power plant concept
Vehicle to Load/Grid
Edit: Heatpump instead of resistive heating, for e.g. Tesla Model 3 also heat pump from/to drive unit/battery as needed