Can you lube sliding windows on the 303?

Hi- We are on our first trip this week and really enjoy the 5er. The sliding windows however, are really difficult to operate. Has anyone found a lubricant or other fix for this? I’m thinking of spray silicone possibly.

Hi Bob, try 3-IN-ONE Window & Track Dry Lube (10oz spray can). I got mine at Walmart for @ $6.- or $7.-

Thanks Martina- I will try that.