check your clutch fluid level,
Have had the same problem twice since having my 370, first time, car was 11 months old with 4500 miles on the clock lost clutch pressure while in Germany, got partial pressure back, but took it to a Nissan dealer there, Nissan replaced the CSC (slave cylinder), master cylinder and the Hydraulic pipe in the bell housing under warranty. Then last year lost pressure again so took it in to my local dealer, again it was a defective CSC, so now I check my clutch fluid weekly just in case. It has been noted as a fault in the US as well and a couple of companies i the US now make a more robust after market replacement for the original.