IsItAGoodCar
Reliability Guide

Common Problems with the
2005 Smart Roadster (452)

We've identified 3 known issues that can affect the 2005 Smart Roadster (452). 2 of these are serious faults that could be expensive to repair.

3
Known Issues
2
Serious
0
Moderate
1
Minor

All Known Issues

Catastrophic Water Ingress

SeriousBodywork & Rust

Water enters through wing mirrors, door seals, the bulkhead, and the rear quarter lights. This often ruins the SAM unit and the carpets.

Est. Repair Cost: £100–£1,500
Warning Signs:

Wet carpets, Mist on the inside of the glass, Electrical gremlins (wipers, lights, starting)

What to Inspect:
  • Lift the carpets and feel the foam backing for water
  • Check the SAM unit for white/green powder (corrosion)
Verified by IsItAGoodCar Research Team

SAM Unit Failure

SeriousElectrics & Electronics

Water tracks down the wiring loom from the wiper tray and enters the SAM unit. This is the most common cause of "dead" Roadsters.

Est. Repair Cost: £500–£1,200
Warning Signs:

Horn sounding continuously, Car won't turn off, Total electrical failure

What to Inspect:
  • Check for the "Evil Twin" modifications (drip loops and covers) to protect the SAM
Verified by IsItAGoodCar Research Team

Snapped Aircon Pipes

MinorElectrics & Electronics

The AC pipes are prone to vibration-induced cracks, leading to total loss of refrigerant.

Est. Repair Cost: £250–£400
Warning Signs:

AC not cold, Visible oily residue on the pipes near the compressor

What to Inspect:
  • Check if the updated flexible AC pipes have been fitted
Verified by IsItAGoodCar Research Team

Buying Tips for 2005 Smart Roadster (452)

  • Water ingress is the absolute priority; check the carpets, the SAM unit (fuse box) under the dash, and the boot for any dampness.
  • Ensure the automated gearbox shifts; the clutch actuator requires regular greasing, and the gearbox mapping should ideally be remapped by a specialist.
  • Inspect the turbocharger on the 698cc engine for smoking or boost leaks; the engine requires meticulous servicing to survive past 70,000 miles.
  • Test the electric folding soft top or removable hardtop for smooth operation and tight seals.
  • Check the air conditioning pipes, which run the length of the car and frequently corrode and leak.
  • Listen for worn wheel bearings and check the condition of the front suspension springs, which are prone to snapping.
2004
Check a 2005 Smart Roadster (452) by Registration