Parking in Shrewsbury

The easiest way is use the park & rides. Enter via the bus lane and wait for the next bus, the drivers are supposed to open the height barriers but often simply tell you to park at the side of the bus area.
Other than the P&R's there is a large car park opposite the abbey with no height barriers and a pleasant walk along the river into town.

Have a look here : [You must be registered and logged in to see this link.] If you click on the name of the car park it tells you opening hours, height restrictions, prices etc. There's also a link to the park and rides.

You could find that walking to a car park takes longer than finding the park and ride stops, which are usually in a main street. I used the one by the garden centre, I think it's Meole Brace, and there's a Little Chef there too if you fancy a bite to eat before you leave.

Nora

You were able to park in the riverside car par and stay overnight and just walk over the footbridge into town, from memory, you needed to arrive early for a space.
Of course, this may not be the case.
Pete

The Riverside car park as suggested by Breakaleg. Parked there last Saturday..approaching from Frankwell is the easiest route in. Look for "Theatre Severn' on Google. The carpark is alongside it.