Toyota MR2: Water ingress from blocked soft-top drain tubes

The W30 MR2 Spyder soft top has four drain tubes routed to exit under the sills. These tubes are narrow and accumulate leaf litter and debris, blocking completely. When blocked, rainwater pools in the roof framework channels and finds its way into the cabin — typically saturating the rear bulkhead carpet, corroding the battery tray, and filling the storage pockets behind the seats. Prolonged water ingress causes ECU connector corrosion and electrical gremlins. The chassis rails in the sill area also rust from inside where standing water collects.

• Damp or musty smell inside cabin
• Wet carpet at rear of cockpit particularly after rain
• Intermittent electrical faults (SMT, windows, instruments) after wet weather
• Visible water staining on rear bulkhead panels

1. 1

   With roof down, pour a small amount of water into the roof channel drains and verify it exits under the sills.

2. 2

   Press the carpet behind seats to check for dampness.

3. 3

   Inspect rear bulkhead for water staining and the battery tray for corrosion.

Parts involved: Chassis and structural rust, Body corrosion.

$200 to $1,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Have the roof drain tubes ever been cleared?”
• “Has there ever been water inside the cabin after rain?”
• “Has the rear carpet been wet or removed for drying?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.