I have family in the Isle of Wight so I always try and find the best price when it comes to getting the car ferry over.
I have found a really good deal this month which is cheaper than I have ever paid before.
Use the code(RT2017) which gives you 20% off the car ferry if you book by the end of January 2017 and the travel dates are before the 23rd of July 2017.
17th February @ 7:30 (Southampton) - 20th February @ 6pm (East Cowes) is £49.20
You can get it cheaper with earlier / later times also and then the price increases with peak times so choose the combination that suits you.
Red Funnel - 20% off stays of 2 nights or more with a car when you book by 31st January 2017 for travel by 23rd July 2017. Excludes 8th - 12th June 2017 (Isle of Wight Festival dates). Valid for standard cars.
Red Funnel discount code: RT2017
There are lots of other discounts available on this page also if needed: http://www.isleofwightguru.co.uk/discount-isle-of-wight-ferry-travel.html