The convertible top may have problems with the micro-switches and potentiometers that help control the raising and lowering of the top.
Several issues occur with the door locks on the Volvo C70 and most are because of the door lock assembly. What happens is that one door will not lock while the other one does. In other cases you will lock the doors and then one of the doors will immediately unlock.
The problem is that the door lock assembly is defective and will need replacement. Replacement of this assembly on the C70 is very difficult and is not recommended by a novice. Getting the door and window aligned properly so that you don't get air or water leaks is very, very difficult.
The upper engine mount may wear prematurely. Symptoms may include a harsh feeling when the transmission is shifting and roughness when the engine is idling. Worn engine mounts should be replaced as necessary.
The anti-lock brake system (ABS) warning light and/or other dash warning lights may illuminate due to a failed ABS Control Module . Replacement of the failed module is generally required to correct this concern.
Several complaints have been reported regarding Volvo C70 transmission shifting issues. Long shift times between gear shifts, hard shifting, hard downshifting and a loss of transmission operation all together to name a few.
If the issue is minor, a transmission software update may fix this issue so if available, the software should be updated before any repairs are made.
There are several technical service bulletins (TSB's) available from Volvo that address these shifting issues and they should be consulted by the repair shop during the automatic transmission diagnostic process.
Regular servicing of the transmission fluid can help with preventing transmission failure, but not in all cases. Follow the suggested fluid replacement interval recommended by Volvo. You will find this in your owners manual, or find it here: http://bit.ly/Volvo_Owners_Manuals
A refrigerant leak may develop from the AC evaporator causing the AC to blow warm air. Verifying failure of this component is difficult. A good shop will use leak detection dye to verify a failing evaporator.
related to engine-cooling, thermostat, location