Saturday's 16-11 defeat to Connacht ended a season where Glasgow never really got going despite reaching the PRO12 play-offs for the fifth time in a row.
Peter told the Evening Times: “Everyone in the dressing room knows that we can still get better by 10 or 20 per cent. We’ve barely fired at all this season. We blew teams away in a couple of games, but apart from that we have played in dribs and drabs.
“We’ve got more than enough firepower to compete. We just have to make sure we work really hard in the pre-season. It will be good to get everyone together right from the start, go into those dark places and work to make sure we improve and we hit the ground running at the start of next season.
"The changing room was gutted. It’s a tough way for the boys who are leaving to be sent off.
“We need to get better. We need to improve, and we will for next season I’m sure.
“We want to be winning every game we’re involved in. That result doesn’t sit well with us at all.
“But credit to Connacht - they played some great rugby and they have stuck with it all year. Today they put us under a lot of pressure and kept the scoreboard ticking over.
“In the ten minutes after half-time we finally got into our shape and we cut them to pieces. If we could have kept a hold of the ball and got into our rhythm I think we could have scored a few tries, but such is life.
“There is plenty to work on and that result will definitely spur us on next season. It was tough, but we certainly left a lot of chances out there. We’re disappointed, but it will spur us on to do better.”